Flagrant Badassery

A JavaScript and regular expression centric blog

JavaScript Date Format

Update: The documentation below has been updated for the new Date Format 1.2. Get it now!

Although JavaScript provides a bunch of methods for getting and setting parts of a date object, it lacks a simple way to format dates and times according to a user-specified mask. There are a few scripts out there which provide this functionality, but I've never seen one that worked well for me… Most are needlessly bulky or slow, tie in unrelated functionality, use complicated mask syntaxes that more or less require you to read the documentation every time you want to use them, or don't account for special cases like escaping mask characters within the generated string.

When choosing which special mask characters to use for my JavaScript date formatter, I looked at PHP's date function and ColdFusion's discrete dateFormat and timeFormat functions. PHP uses a crazy mix of letters (to me at least, since I'm not a PHP programmer) to represent various date entities, and while I'll probably never memorize the full list, it does offer the advantages that you can apply both date and time formatting with one function, and that none of the special characters overlap (unlike ColdFusion where m and mm mean different things depending on whether you're dealing with dates or times). On the other hand, ColdFusion uses very easy to remember special characters for masks.

With my date formatter, I've tried to take the best features from both, and add some sugar of my own. It did end up a lot like the ColdFusion implementation though, since I've primarily used CF's mask syntax.

Before getting into further details, here are some examples of how this script can be used:

var now = new Date();

// Returns, e.g., 6/09/07

// Can also be used as a standalone function
dateFormat(now, "dddd, mmmm dS, yyyy, h:MM:ss TT");
// Saturday, June 9th, 2007, 5:46:21 PM

// You can use one of several named masks
// 2007-06-09T17:46:21

// ...Or add your own
dateFormat.masks.hammerTime = 'HH:MM! "Can\'t touch this!"';
// 17:46! Can't touch this!

// When using the standalone dateFormat function,
// you can also provide the date as a string
dateFormat("Jun 9 2007", "fullDate");
// Saturday, June 9, 2007

// Note that if you don't include the mask argument,
// dateFormat.masks.default is used
// Sat Jun 09 2007 17:46:21

// And if you don't include the date argument,
// the current date and time is used
// Sat Jun 09 2007 17:46:22

// You can also skip the date argument (as long as your mask doesn't
// contain any numbers), in which case the current date/time is used
// 5:46:22 PM EST

// And finally, you can convert local time to UTC time. Either pass in
// true as an additional argument (no argument skipping allowed in this case):
dateFormat(now, "longTime", true);
now.format("longTime", true);
// Both lines return, e.g., 10:46:21 PM UTC

// ...Or add the prefix "UTC:" to your mask.
now.format("UTC:h:MM:ss TT Z");
// 10:46:21 PM UTC

Following are the special characters supported. Any differences in meaning from ColdFusion's dateFormat and timeFormat functions are noted.

Mask Description
d Day of the month as digits; no leading zero for single-digit days.
dd Day of the month as digits; leading zero for single-digit days.
ddd Day of the week as a three-letter abbreviation.
dddd Day of the week as its full name.
m Month as digits; no leading zero for single-digit months.
mm Month as digits; leading zero for single-digit months.
mmm Month as a three-letter abbreviation.
mmmm Month as its full name.
yy Year as last two digits; leading zero for years less than 10.
yyyy Year represented by four digits.
h Hours; no leading zero for single-digit hours (12-hour clock).
hh Hours; leading zero for single-digit hours (12-hour clock).
H Hours; no leading zero for single-digit hours (24-hour clock).
HH Hours; leading zero for single-digit hours (24-hour clock).
M Minutes; no leading zero for single-digit minutes.
Uppercase M unlike CF timeFormat's m to avoid conflict with months.
MM Minutes; leading zero for single-digit minutes.
Uppercase MM unlike CF timeFormat's mm to avoid conflict with months.
s Seconds; no leading zero for single-digit seconds.
ss Seconds; leading zero for single-digit seconds.
l or L Milliseconds. l gives 3 digits. L gives 2 digits.
t Lowercase, single-character time marker string: a or p.
No equivalent in CF.
tt Lowercase, two-character time marker string: am or pm.
No equivalent in CF.
T Uppercase, single-character time marker string: A or P.
Uppercase T unlike CF's t to allow for user-specified casing.
TT Uppercase, two-character time marker string: AM or PM.
Uppercase TT unlike CF's tt to allow for user-specified casing.
Z US timezone abbreviation, e.g. EST or MDT. With non-US timezones or in the Opera browser, the GMT/UTC offset is returned, e.g. GMT-0500
No equivalent in CF.
o GMT/UTC timezone offset, e.g. -0500 or +0230.
No equivalent in CF.
S The date's ordinal suffix (st, nd, rd, or th). Works well with d.
No equivalent in CF.
'…' or "…" Literal character sequence. Surrounding quotes are removed.
No equivalent in CF.
UTC: Must be the first four characters of the mask. Converts the date from local time to UTC/GMT/Zulu time before applying the mask. The "UTC:" prefix is removed.
No equivalent in CF.

And here are the named masks provided by default (you can easily change these or add your own):

Name Mask Example
default ddd mmm dd yyyy HH:MM:ss Sat Jun 09 2007 17:46:21
shortDate m/d/yy 6/9/07
mediumDate mmm d, yyyy Jun 9, 2007
longDate mmmm d, yyyy June 9, 2007
fullDate dddd, mmmm d, yyyy Saturday, June 9, 2007
shortTime h:MM TT 5:46 PM
mediumTime h:MM:ss TT 5:46:21 PM
longTime h:MM:ss TT Z 5:46:21 PM EST
isoDate yyyy-mm-dd 2007-06-09
isoTime HH:MM:ss 17:46:21
isoDateTime yyyy-mm-dd'T'HH:MM:ss 2007-06-09T17:46:21
isoUtcDateTime UTC:yyyy-mm-dd'T'HH:MM:ss'Z' 2007-06-09T22:46:21Z

A couple issues:

  • In the unlikely event that there is ambiguity in the meaning of your mask (e.g., m followed by mm, with no separating characters), put a pair of empty quotes between your metasequences. The quotes will be removed automatically.
  • If you need to include literal quotes in your mask, the following rules apply:
    • Unpaired quotes do not need special handling.
    • To include literal quotes inside masks which contain any other quote marks of the same type, you need to enclose them with the alternative quote type (i.e., double quotes for single quotes, and vice versa). E.g., date.format('h "o\'clock, y\'all!"') returns "6 o'clock, y'all". This can get a little hairy, perhaps, but I doubt people will really run into it that often. The previous example can also be written as date.format("h") + "o'clock, y'all!".

Here's the code:

 * Date Format 1.2.3
 * (c) 2007-2009 Steven Levithan <stevenlevithan.com>
 * MIT license
 * Includes enhancements by Scott Trenda <scott.trenda.net>
 * and Kris Kowal <cixar.com/~kris.kowal/>
 * Accepts a date, a mask, or a date and a mask.
 * Returns a formatted version of the given date.
 * The date defaults to the current date/time.
 * The mask defaults to dateFormat.masks.default.

var dateFormat = function () {
	var	token = /d{1,4}|m{1,4}|yy(?:yy)?|([HhMsTt])\1?|[LloSZ]|"[^"]*"|'[^']*'/g,
		timezone = /\b(?:[PMCEA][SDP]T|(?:Pacific|Mountain|Central|Eastern|Atlantic) (?:Standard|Daylight|Prevailing) Time|(?:GMT|UTC)(?:[-+]\d{4})?)\b/g,
		timezoneClip = /[^-+\dA-Z]/g,
		pad = function (val, len) {
			val = String(val);
			len = len || 2;
			while (val.length < len) val = "0" + val;
			return val;

	// Regexes and supporting functions are cached through closure
	return function (date, mask, utc) {
		var dF = dateFormat;

		// You can't provide utc if you skip other args (use the "UTC:" mask prefix)
		if (arguments.length == 1 && Object.prototype.toString.call(date) == "[object String]" && !/\d/.test(date)) {
			mask = date;
			date = undefined;

		// Passing date through Date applies Date.parse, if necessary
		date = date ? new Date(date) : new Date;
		if (isNaN(date)) throw SyntaxError("invalid date");

		mask = String(dF.masks[mask] || mask || dF.masks["default"]);

		// Allow setting the utc argument via the mask
		if (mask.slice(0, 4) == "UTC:") {
			mask = mask.slice(4);
			utc = true;

		var	_ = utc ? "getUTC" : "get",
			d = date[_ + "Date"](),
			D = date[_ + "Day"](),
			m = date[_ + "Month"](),
			y = date[_ + "FullYear"](),
			H = date[_ + "Hours"](),
			M = date[_ + "Minutes"](),
			s = date[_ + "Seconds"](),
			L = date[_ + "Milliseconds"](),
			o = utc ? 0 : date.getTimezoneOffset(),
			flags = {
				d:    d,
				dd:   pad(d),
				ddd:  dF.i18n.dayNames[D],
				dddd: dF.i18n.dayNames[D + 7],
				m:    m + 1,
				mm:   pad(m + 1),
				mmm:  dF.i18n.monthNames[m],
				mmmm: dF.i18n.monthNames[m + 12],
				yy:   String(y).slice(2),
				yyyy: y,
				h:    H % 12 || 12,
				hh:   pad(H % 12 || 12),
				H:    H,
				HH:   pad(H),
				M:    M,
				MM:   pad(M),
				s:    s,
				ss:   pad(s),
				l:    pad(L, 3),
				L:    pad(L > 99 ? Math.round(L / 10) : L),
				t:    H < 12 ? "a"  : "p",
				tt:   H < 12 ? "am" : "pm",
				T:    H < 12 ? "A"  : "P",
				TT:   H < 12 ? "AM" : "PM",
				Z:    utc ? "UTC" : (String(date).match(timezone) || [""]).pop().replace(timezoneClip, ""),
				o:    (o > 0 ? "-" : "+") + pad(Math.floor(Math.abs(o) / 60) * 100 + Math.abs(o) % 60, 4),
				S:    ["th", "st", "nd", "rd"][d % 10 > 3 ? 0 : (d % 100 - d % 10 != 10) * d % 10]

		return mask.replace(token, function ($0) {
			return $0 in flags ? flags[$0] : $0.slice(1, $0.length - 1);

// Some common format strings
dateFormat.masks = {
	"default":      "ddd mmm dd yyyy HH:MM:ss",
	shortDate:      "m/d/yy",
	mediumDate:     "mmm d, yyyy",
	longDate:       "mmmm d, yyyy",
	fullDate:       "dddd, mmmm d, yyyy",
	shortTime:      "h:MM TT",
	mediumTime:     "h:MM:ss TT",
	longTime:       "h:MM:ss TT Z",
	isoDate:        "yyyy-mm-dd",
	isoTime:        "HH:MM:ss",
	isoDateTime:    "yyyy-mm-dd'T'HH:MM:ss",
	isoUtcDateTime: "UTC:yyyy-mm-dd'T'HH:MM:ss'Z'"

// Internationalization strings
dateFormat.i18n = {
	dayNames: [
		"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat",
		"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"
	monthNames: [
		"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec",
		"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"

// For convenience...
Date.prototype.format = function (mask, utc) {
	return dateFormat(this, mask, utc);

Download it here (1.2 KB when minified and gzipped).

Note that the day and month names can be changed (for internationalization or other purposes) by updating the dateFormat.i18n object.

If you have any suggestions or find any issues, lemme know.

New library: Are you a JavaScript regex master, or want to be? Then you need my fancy XRegExp library. It adds new regex syntax (including named capture and Unicode properties); s, x, and n flags; powerful regex utils; and it fixes pesky browser inconsistencies. Check it out!

There Are 314 Responses So Far. »

  1. Nice work!. I was using cfjs library (http://cfjs.riaforge.org/) which impliments a DateFormat and TimeFormat functions. I’ll point the guy to your post.

  2. Steve,

    Nice work on this DateFormat function. I like it. :o) I’m wondering if cfjs users would be confused by the added functionality (basically making TimeFormat unnecessary). But it wouldn’t be the first function in CFJS that doesn’t behave *exactly* like its CF counterpart. The added niceness is that it would decrease the size of the overall library since TimeFormat would go away (or maybe be aliased to DateFormat).

    So, would you mind terribly if I integrated it with the CFJS libraries?


  3. Also, I love the name of you blog. LOL! :o)

  4. @Chris Jordan,

    It’s MIT licensed, so feel free. Of course, I would appreciate it if you kept a link back to my site.

  5. @Steve,

    Oops! Didn’t see the license. Thanks! And of course I’ll include a link back! :o)


  6. I may have found a bug.

    I tried the following example from your blog post, but using CFJS’ implementation:

    alert($.DateFormat(new Date(), “It’s dddd”));

    and what I got as a response was:

    It’22 Thursday

    In other words, the function interpreted the s to mean seconds and not the literal character ‘s’.

    I can’t see that any changes I made would have caused this.

    Any thoughts?

  7. It’s not a bug, but rather a case of where testing my own examples would have been a good idea. The single quote creates a word boundary, and as explained, mask sequences are special when they’re preceded and followed by a word boundary (as defined by the \b regex metasequence, which does not do any lexical analysis).

    I’ve modified the unpaired quote example and noted that quote marks count as word boundaries.

    Do you think the code would benefit from adjusting the special character escaping mechanism? If so, do you have any suggestions? I’d be interested in any feedback on this. However, I’d rather avoid complex implementations which rely on mimicking lookbehind, for example.

  8. Thanks for your work on this, you have no idea how much time you saved me from “recreating the wheel”. I do have one quesiton that really confused me while using your script. When i specified the ‘Z’ param, the script was returning locale time and the time zone as being UTC. Could something be set incorrectly in my browser, or am I just mis-interpretting the output from this script?

  9. Eric, the timezone is extracted from the toUTCString method’s value. What do you see in your browser when you run the following line of code?

    alert(new Date().toUTCString());

  10. I am also trying to find a way to display the local timezone abbreviation.
    When I ran alert(new Date().toUTCString());, I get the following:

    Mon, 16 Jul 2007 16:39:09 GMT

    IE 7.0.5730.11
    Mon, 16 Jul 2007 16:39:21 UTC

    I wonder how you are able to get EST, PST, etc.

  11. Adrienne, that’s a good question! This was apparently a brainfart on my part. I’ve removed the “Z” flag (and upped the version number to 0.2), because the results I claimed it would provide would in fact be more difficult to produce reliably, and as a result are beyond the scope of this function.

    To get the name of the client’s time zone in long form (also accounting for daylight savings), you could use date.toString().replace(/^.*\(|\)$/g, ""). On my system, that presently returns “Eastern Daylight Time”. To get “EDT” from that, you could add .replace(/[^A-Z]/g, ""). However, this stuff might not be reliable internationally.

  12. I like it! Clever. Fantastically clever.

    Although the time-zone formatting is a little off – in IE and Opera, you’ll get “MOCST” or “MOGMT”, depending on what your local time zone is. I tweaked with it a little, and the following seems rock-solid across browsers (and across international timezones, and in Opera, which doesn’t seem to recognize the timezone names, just GMT+offset). It’s a mouthful for sure, so you’d be wise to just split the first part off into a variable like var timeZone = /mouthful/g.

    case “Z”: return (d.toString().match(/\b(?:(?:(?:Pacific|Mountain|Central|Eastern|Atlantic)\s+|[PMCEA])(?:(?:Standard|Daylight|Prevailing)\s+|[SDP])(?:Time|T)|(?:GMT|UTC)(?:[+-]\d{4})?)\b/g) || [""]).pop().replace(/[^A-Z0-9+-]/g, “”);

    The pop() part is for Mozilla, which contains both GMT+offset and the friendly title in its default toString(). Might as well return the friendly-name one, if the browser provides it.

    Again, thanks for this! Awesome to see good code exploiting the function-argument capabilities of replace(). ^_^

  13. @Scott Trenda, thanks! I’ve implemented your timezone handling (with a couple very minor changes), and brought back the Z flag. I’ve also changed the code so that the regexes and inner zeroize function are cached through closure. The version number has been upped to 0.4.

  14. You’re very welcome! Like I said, I love tweaking code that’s smart to start with.

    Not that it’d change the logic or significantly affect the performance one way or another, but here’s an alternate zeroize() function for you. A bit cleaner in my eyes, as it doesn’t use any temp variables, and doesn’t choke if no arguments are passed.

    function padZero (num, length) {
        num = String(num);
        length = parseInt(length) || 2;
        while (num.length < length)
            num = "0" + num;
        return num;

  15. “I love tweaking code that’s smart to start with.” –Scott Trenda

    You and me both. :)

    Personally, I don’t care about protecting against invalid length values since zeroize (now just called pad, though it still only uses zeros) is private. However, avoiding the temp vars is definitely nicer so I’ve added that (now at v0.4.1).

    For the record, I certainly welcome these kinds of tweaks! They’re easy to miss, and most people don’t bother to point such things out. Thanks again.

  16. Hi Steve, Scott,

    Can you please post the final version of the your timezone handling javascript code?


  17. var timeZoneStr = todayDate.toString().replace(/^.*\(|\)$/g, “”).replace(/[^A-Z]/g, “”);

    returns PST

    timeZoneStr = todayDate.toString().match((/\b(?:(?:(?:Pacific|Mountain|Central|Eastern|Atlantic)\s+|[PMCEA])(?:(?:Standard|Daylight|Prevailing)\s+|[SDP])(?:Time|T)|(?:GMT|UTC)(?:[+-]\d{4})?)\b/g) || ['']).pop().replace(/[^A-Z0-9+-]/g, ”);

    returns GMT +0800

  18. I would like to get the PST or EST or AST etc string from the javascript date object (for all the browsers with all different international time zones).

    If you can post your updated code that will be great.

  19. @Cynthia:

    What browser, OS, timezone, and locale/language are you using, and what do you see when you run the code alert(new Date().toString())? I’m going to post a new version of this script soon (including some new features as well as more code refactoring from Scott), so your help with this is appreciated.

    BTW, the regex Scott posted (the long one) matches full and abbreviated US timezone names as well as the UTC offset, if included, from the value returned by running toString() on a Date object. It then grabs just the last match in case there was more than one (since from both of our testing, the last match has been the preferable one), and clips extra characters. For non-US timezones or with the Opera browser (which doesn’t include timezone names in its toString() value), or in the case of browsers/configurations we have not considered which include the offset and timezone name in reversed order, this returns the UTC offset.

  20. Edit (Steve): Since it was stretching the page, I’ve replaced all instances of the first, shorter code from Cynthia’s last comment with [REGEX1], and all instances of the second, longer code with [REGEX2].

    Hi Steve,

    Using Firefox: toString() returns: Sun Nov 11 2007 15:53:28 GMT-0800 (Pacific Standard Time)
    [REGEX1] returns PST
    [REGEX2] returns PST

    Using IE7: toString() returns: Sun Nov 11 15:58:36 PST 2007
    [REGEX1] returns PST
    [REGEX2] returns PST

    If I change the time zone to IST, I get the following results (both IE and Firefox):
    [REGEX1] returns PST
    [REGEX2] returns GMT +0800

  21. Cynthia, what is the value of new Date().toString() when your timezone is “IST”?

    In any case, note that [REGEX2] (the “Z” flag handling) only supports abbreviations for US timezones, which is now noted in the documentation on this page. For other timezones or for all timezones in the Opera browser, it returns the GMT/UTC offset. That’s unfortunate, but I am not aware of any official, internationally recognized timezone abbreviation list. Taking just the uppercase letters from the full timezone names would be unreliable, and in any case it would sometimes overlap with the US timezone names. Use the new “o” flag for reliable GMT/UTC offsets regardless of the timezone, region, or language of your users’ browsers.

  22. I’ve just updated Date Format to version 1.0, and updated the documentation in this blog post along with it. 1.0 includes the new “o” (offset) flag and enhancements for code brevity provided by Scott Trenda, along with several new features, including a standalone dateFormat function, named and default masks (plus you can easily add your own), the ability to specify the date to format via a string, easier internationalization, etc. Check it out!

    1.0 includes one change which is not backwards compatible: mask characters and sequences no longer have to comprise entire words for them to be treated specially. The former handling was intended to make it dead-easy to mix literal characters into date masks, but ended up being a nuisance since most people had no need to use the code to embed dates in larger strings.

  23. Using Firefox: toString() returns: Mon Nov 12 2007 08:03:43 GMT+0530 (India Standard Time)

    Using IE7: toString() returns: Mon Nov 12 08:03:06 UTC+0530 2007

  24. Well, there you have it. There is simply no good way to pull “IST” from IE7′s value without building a comprehensive list of international timezone name abbreviations, which as far as I know doesn’t exist anyway. There is also no way either of the regexes could have pulled “PST” from either of those values, so I think you might have confused that with your Pacific timezone tests in your earlier comments.

    As noted previously, the “Z” flag supports US timezones only. Use the “o” flag for reliable GMT/UTC offsets.

  25. [...] just updated my ColdFusion-inspired JavaScript Date Format script to version 1.0, and updated the documentation in the old post along with it. 1.0 includes [...]

  26. Kris Kowal integrated Date Format 1.0 as a module into his innovative, emerging JavaScript library called Chiron. In the process, he changed it so that if only one argument is provided to dateFormat and that argument contains no numbers, it’s treated as a mask and applied to the current date and time. I think that was a great change, so I’ve added it in version 1.1, and updated the above documentation. Thanks, Kris!

  27. Great work! It appears however the documentation has month and minutes backwards. MM is returning month and mm is returning minutes. According to the doc it is suppose to be the reverse.


  28. @Pipnaintez, I can’t reproduce the problem you mention. “mm” returns months, and “MM” returns minutes, like the docs say.

  29. Hi Steve!

    I used your code as a base for reconstructing the PHP date() function in JavaScript. It supports most features that PHP’s date() function does, but takes milliseconds rather than seconds as the timestamp.

    I haven’t implemented all format characters yet (they will be replaced by ‘?’), so if anyone feels up for it, feel free to code them as well. The code hasn’t been tested thoroughly either.

    Here it is: http://javascript.mezane.org/date/date.js

  30. Is there any way to display time with the timezone that matches the offset rather than the browser’s local timezone? I want to display the time somewhere else in the world with their local timezone – not my local timezone.

  31. Good job Steven,

    Was very much helpful.

  32. Steven, thanks for writing this great function. I like your nod to ColdFusion and the similarity your function shares.

  33. How will you add Alaska (ALA, ALAW) and Hawaii (HAW) time zone to the Z.

  34. Very nice work, thanks! I will try to create a version with syntax closer to the Java Date class.

  35. Hi,

    Can u tell me how to use this function with a timestamp in isoFullDateTime format, from the xml and convert it to a UTC format. I’m getting and invalid date error when i pass this as
    var d= segment.traveltime;
    alert(d); //is fine
    var datestring22 = dateFormat(d, “fullDate”); //gives invalid date error

  36. Hi I’m sorry but I don’t understand something..I wrote “dateFormat(date,”dd-mm-yyyy”);” I allways have a message “uncaught exception: invalid date”.
    Does someone can help me please ?
    (Sorry for my English…)

  37. Oups I forgot that date is “18-06-2008″

  38. @RM, what is UTC format? It sounds like you’re running into the same issue as jp clutier (see below).

    @jp clutier, this function uses the native Date.parse method to convert a date passed in as a string to a Date object. The format you specified is not recognized by the somewhat limited Date.parse. You’ll need to either use a string that the parse method recognizes, or create the date using the Date constructor (e.g., new Date(year, month, date)).

  39. Thanks for an awesome script! Works like a charm!

    I have a suggestion though that might be useful… I ran into the need to have the ‘st’, ‘nd’, ‘rd’, or ‘th’ appended to the end of the day (eg: 1st, 2nd, 3rd, 4th, etc…).

    The solution was simple, Just add a method as follows:

    postFix = function (value) {
    if (value == 1 || value == 21 || value == 31) {
    return value + “st”;
    } else if (value == 2 || value == 22) {
    return value + “nd”;
    } else if (value == 3 || value == 23) {
    return value + “rd”;
    } else {
    return value + “th”;

    Then you can create new flags as follows:

    dp: postFix(d),
    ddp: postFix(pad(d)),

    It’s really simple, I know, but I just thought it might be something you’d like to include.

  40. Ok… scratch that about the flags… for some reason, if you put ‘dp’ (for example) into the mask, it comes back with something like ’9p’ instead of ’9th’!?

    Any clues?

  41. @switch, you probably didn’t add your new flags to the token regex.

    I liked the idea of a flag for ordinal suffixes, so I’ve gone ahead and added it to the script and upped the version to 1.2. Here are the changes (the above post has been updated accordingly):

    – The new S flag outputs date ordinal suffixes (“st”, “nd”, “rd”, “th”). Works well with d. E.g., dateFormat("mmmm dS, yyyy") returns “July 4th, 2008″.
    – Added support for converting local time to UTC time before applying the format mask, via the third argument (Boolean) or the UTC: mask prefix (which allows applying UTC time via a named mask).
    – Several changes to the provided, named masks.

    The named mask changes:

    default changed from “ddd mmm d yyyy HH:MM:ss” to “ddd mmm dd yyyy HH:MM:ss” so that the default format is a fixed width that is easier to parse, and matches Firefox’s Date.prototype.toString (minus the time zone info).
    – Removed isoFullDateTime (was “yyyy-mm-dd’T'HH:MM:ss.lo”).
    – Added isoUtcDateTime (is “UTC:yyyy-mm-dd’T'HH:MM:ss’Z'”, which uses the new UTC conversion prefix).

  42. Here’s a complete list of time zone abbreviations.
    There are quite a few overlaps.

  43. OMG… such a simple mod!!! Where were you when they created this abomination called Javascript!!!

  44. Can I convert ISO formatted date(string) ex: 2008-08-08T10:10+00:00 to a Date object using dateFormat?

  45. Hi

    great job, but there is small bug in dayNames array:
    dayNames: [
    "Sun", "Mon", "Tue", "Wed", "Thr", "Fri", "Sat",
    "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"

    The short name for thursday should be “Thu”.


  46. @ArunB, this function only returns a string; never a Date object. The input strings it can interpret as a date are only those supported by JavaScript’s native Date.parse (which doesn’t support the format you specified). In any case, there is a lot of variety in the formats that are considered ISO formatted date strings. This library includes named masks to output the most common formats.

    @Tyler, good catch. Thanks. I’ve corrected the abbreviation and upped the version to 1.2.2.

  47. The date format method is great and has saved me a bunch of time, but I’ve just noticed that the following line causes the function to fail in firefox 3:

    if (isNaN(date)) throw new SyntaxError(“invalid date”);

    Has anyone else noticed this?

    alert(cs_formatDate(’2008-08-15 15:30:11′));

  48. Please ignore my ignorance regarding the above, it turns out that the dashes in the date weren’t ALL being replaced (for forward slashes) prior to being passed to objDate.format(), so absolutely nothing to do with the script… ahem.. cough!

    The date format script is great! Many thanks!

  49. Thanks so much. Cool script.

  50. Thanks bro, an excellent script

  51. Hi Steven,

    First of all great job Steven. Thanks for the script. You saved my work. I am a newbie in javascript. I also need to write a function where the input format is always in yyyy-MM-dd and I have convert this to different formats (into different country formats). How can I do this with this script? Do I have make any changes to the script? Please help me on this.


  52. Hi Steven,

    Great code!
    I’ve just added 2 new functions:

    Number.prototype.toDate = function (mask, utc) {
    return new Date(this).format(mask, utc);
    String.prototype.toDate = function (mask, utc) {
    return new Date(this).format(mask, utc);

    Jardel Weyrich

  53. [...] if you work with Javascript and need to use dates/times, you should absolutely check out a JS library for formatted dates and times by Steven Levithan (who is obviously cool; his blog is titled “Flagrant [...]

  54. Thanks a lot for this. Worked perfectly out of the box, saved me lots of time. :)

  55. Hi Steven,

    Nice article. I don’t see, however, any comments to follow on Pipnaintez’s post, i.e. ‘MM’ returns Months, and ‘mm’ returns minutes. I have currently tested under IE6/7/8, Firefox2/3, Safari, Opera and Chrome. They all confirm it.

  56. @Veli, as I responded to @Pipnaintez just below his comment, that’s not true. In this library, “mm” returns months and “MM” returns minutes, like the above documentation says. This differs from some other date formatting libraries.

  57. You have provided good information. I was thinking a lot how could i do the date format and finally when i saw your site everything got cleared. Thank you

  58. Hi, could you help me formatting this date “Mon Oct 20 19:00:00 EDT 2008″? As long as I checked the Date.parse() does not support such DateFormat, but I want to be sure.

    dateFormat(‘Mon Oct 20 19:00:00 EDT 2008′,’mmmm dS, yyyy h:MM TT’) = October 21st, 2008 2:00 AM

    Is it possible to have as a result “October 20th, 2008 7:00 PM” – I need just some formatting, but the script should not use the user’s clock.

    Thank You!

    PS: The library is just great! Thanks, Steve!


  59. I just want to share my insight on why MM and mm may be confused. If you are wondering why MM and mm are reveresed make sure you are not overriding the format method through some other library. In my case it was ASP.NET Ajax ScriptManager (which is quite hideous because you do not really see the javascript in the sourcecode but it is referenced through some WebResource.axd handler) but it may be another js script. In this case you are just using another library even if it looks like this one:)

  60. Thanks, just what i wanted.

  61. I’ve taken this prototype and modified it to work with SQL date format styles for interaction with a SQL server backend.

    However, I realise I need a date validation function for inputs that can handle date formats in the same styles. I.e. pass a date string and a mask and verify whether the date is valid based on the mask.

    Can anyone recommand anything that does this?

  62. There’s a bug in the dateFormat function’s argument tests that means you can’t pass a mask pattern or name that includes digits or it will be mistaken for a date string.

    The bug is caused by this test -> !/\d/.test(date)

    Short of not passing mask patterns or names that include digits, I’m not sure how best to avoid this.

  63. Hi, could you please help me formatting this date “Sat Aug 10 00:00:00 UTC+0530 2024″?
    The date value stored in excel sheet is in this format “08/03/26″.
    But when I try to fetch the date from the same excel sheet it is showing in the following format “Sat Aug 10 00:00:00 UTC+0530 2024″.

    Is it possible to have as a result in the format “yy/mm/dd” i.e. “08/03/26″ – I need just some formatting using javascript.

  64. @Anthony, that’s not a bug. The behavior is documented above: “You can also skip the date argument (as long as your mask doesn’t contain any numbers), in which case the current date/time is used.”

    Remember that dateFormat() takes a date as it’s first argument. The ability to skip the date argument is merely provided as a convenience. To pass in the current date, you can simply use new Date(). You could also store your mask as a named mask, and use it that way (with the same limitation that the mask name not include numbers if you want to be able to skip the date argument).

  65. Hi, Steven, thanks for your reply and my apologies for not reading your notes closely enough.

    I’m basing my modified version on the date format styles listed here -

    What I’ve decided to do instead is use a standard array rather than an associative array and pass a number (the SQL date style) as the index into the mask array (or a mask string as you allow).

    This seems to work quite well. Still not making much headway with date validation based on a mask though.

  66. @Anthony, here’s a quick function I created for you that validates a date string according to a date mask (using the same flags as dateFormat). It depends on the dateFormat.i18n object from the Date Format script. I’ve only briefly tested it, and a known issue is that it doesn’t validate that a date actually exists (e.g., the “dd” flag will always allow “31″, even for months without 31 days). Hopefully it meets your needs or at least gets you further along. Essentially it uses the mask provided as the second argument to dynamically construct a regex that is then used to validate the date string provided as the first argument.


  67. Hi, Steven. I incorporated a subset of your code (for just the dmy patterns I’m interested in) into the date validate function I’ve been writing. I’ve gone further along with the validate but I’ve hit some snags.

    I liked your regexp patterns so I so swapped mine with them but I think I may have to go back to mine.

    Here’s some code snippets that will help illustrate the problems I still have -

    function validDate(date, mask)
    var token = /d{1,2}|m|M|y/g,
    flags =
    d: “([1-9]|[12]\\d|3[01])”,
    dd: “(0[1-9]|[12]\\d|3[01])”,

    escape = function(str){return str.replace(/[[\]{}()*+?.\\^$|]/g, “\\$&”)},
    re = new RegExp(escape(mask).replace(token, function($0){return flags[$0]}), “i”)

    if (re.test(date))
    var darr = date.match(re),

    At this point I get an array of the match patterns for further checking but I found that if I gave it a date string of “2008/feb/31″ and a mask of “y/M/d” (I’m using M to represent a month name), I get “3″ for the day rather than the expected “31″. So the globbing is non-greedy.

    I think now that I should grab as many digits as there are in between separators (although that may hose me for one of the SQL patterns that has no separators – unless I add more mask flags) and do some checks like are there the expected number of digits.

    Next bit of code (follows directly on from the above) -

    types =
    y: 0,
    M: 1,
    m: 1,
    d: 2,
    dd: 2
    marr = (mask.replace(token, function($0){return types[$0]})).match(/\d/g),
    dtarr = [0, 0, 0],

    for (var i = 0; i -1 ? x : parseInt(darr[i + 1], 10) – 1
    dtarr[marr[i]] = parseInt(darr[i + 1], 10)

    Here I manipulate the mask to work out which parts of the arrays are the which date parts. It works OK except that the indexOf() expects an exact match. So If “dec” or “DEC” is passed I need to manipulate it first in order to match “Dec”. Perhaps the easiest fix is to make the short month name array all uppercase and call toUpperCase() on the indexOf() arg.

    The last problem was here (next piece of code) -

    testdate = new Date(dtarr[0], dtarr[1], dtarr[2])

    It turns out that Date() doesn’t barf if you pass (2007, 1, 31) but instead advances the date to March. This isn’t really a problem because I can use my old code to check the number of days against the month and test the Feb days but I was planning to pass the date string to the dateFormat function and return a correctly formatted one.

    Anyway, I hope the above is of some use to you or anyone else.

  68. Oops, the for loop got messed up (I didn’t escape the entities). Here it is again -

    for (var i = 0; i < 3; i++)
    if (marr[i] == 1)
    x = dateFormat.i18n.indexOf(darr[i + 1])
    dtarr[marr[i]] = x > -1 ? x : parseInt(darr[i + 1], 10) – 1
    dtarr[marr[i]] = parseInt(darr[i + 1], 10)

  69. OK, I have it all working now. Thanks for you help, Steven.

  70. Does this work with Mac?

  71. Sorry my bad, it works.

  72. I’m struggling on how to implement this for use in the following:

    Scenario – I’m attempting to reformat a story.pubDate call in a RSS grab using the following:

    <a href=”>( –

  73. Oops, filtered:

    var xmlContent = crawler.getXML("http://somewhere.com/rss.xml&quot;);
    for each(story in xmlContent.channel.item){
    <li><a href=’<?=story.link?>’>[?=story.title?></a><br>(<?=story.pubDate?>)</li>

  74. Hi,
    Thanks for the date. I have used it and very happy with it, But I also wanted to capture a day after the selected date. Is there a easy way to do it.

  75. Fantastic script!
    This will need to be made a jQuery plugin!

  76. I found a bug in the code that causes the routine to parse the 12-hour “h” incorrectly when running on the Rhino Javascript engine.

    When parsing a lowercase “h” for 12-hour hours, Rhino always evaluates this to “true”. For instance, this mask:

    mm/dd/yyyy h:MM:ss TT

    Would cause the code to output something like this:

    12/02/2008 true:10:08 PM

    The problem is with these lines:

    h: H % 12 || 12,
    hh: pad(H % 12 || 12),

    In Rhino, anything that uses the Logical OR operator || results in a true/false result. “Anynumber OR 12″ always evaluates to “true” – so that’s what it spits out. Interestingly enough, in most browsers I have tested, this problem doesn’t exist.

    My somewhat inelegant solution is to change the lines thus:

    h: H % 12 + (H % 12==0?12:0),
    hh: pad(H % 12 + (H % 12==0?12:0)),

    On my Rhino engine, this solves the problem, and does not break the implementation on any of the browser Javascript engines that I have tested.

  77. One more problem with the Rhino engine, similar to the one above. Inside the pad function:

    len = len || 2;

    It can be fixed by changing it to:

    len = Number(len)?len:2;

  78. Hi.

    I have problem with this script. I need script for formating dates and this looks like it has everything I need. But I can’t make it work. I’m not javascript expert, so this question might sound ridiculous. I copied that source code on my website in tags, and tried to run your examples, but nothing happens.
    After that I put that code in 1st JavaScript Editor, and tried to check that code for syntax errors, and it didn’t pass. Program is claiming that in following lines

    return mask.replace(token, function ($0) {
    return $0 in flags ? flags[$0] : $0.slice(1, $0.length – 1);

    it sees error “Identifier Expected”. He puts cursor behind key word “in”.

    Could sb help me ?

  79. Thanks for this! It was exactly what I needed. It’d be cool to combine this with some of the other Javascript date libraries. Then a developer can choose to conditionally download the components that they need to use. I’d combine this with my Rails-like date helpers.

  80. Very nice – Thank you.

  81. [...] for this, so you’ll need to roll your own. There are hundreds of examples on the web – GIYF – e.g. http://blog.stevenlevithan.com/archi…te-time-format However, a *much* better solution is to provide a date picker so that you never need to worry [...]

  82. Hi..

    I Called date function as ‘dateFormat(now, “dddd, mmmm dS, yyyy, h:MM:ss TT”);’ in between html code, but its not showing the Date..

    How to Call this function?

  83. I wanted to take a few moments to say thank you for this article, it really helped me solve a recent development issue, have a great week.

  84. Really Gr8!!

    Very nice thing…very easy to implement.

  85. I was searching up and down for date format and validation in javascript and found your post. It’s really helpful. Thanks a lot.

  86. [...] Note: for formatting of JavaScript dates, I’ve used date.format.js from stevenlevithan.com. [...]

  87. Is there a reason for using “m” for months and “M” for minutes, when the standards are saying quite the opposite?

    It seems like it is very hard to find a function that will do “parse” operation for a given date string. All functions are doing some kind of “guessing” on the date pattern. There is no solution that actually accepts a date pattern.

  88. @bashan, regarding your question, there are numerous, conflicting standards (open, proprietary, and de facto) for date formatting. If MM and mm were reversed, I’d also want to change the casing of about a dozen other tokens. Rather than getting into all the subjective reasoning behind the chosen tokens, I’ll just state that changing them at this point is unfeasible since a lot of people are already using this script.

  89. According to me the following also will work for get day of the week:

    var mydate = new Date();
    var myweekday= mydate.getDay();

  90. Good work. Thanks.

  91. [...] http://blog.stevenlevithan.com/archives/date-time-format [...]

  92. Awesome – exactly what I needed….saving me some time. Thanks!

  93. Wow, this is really generous. Works GREAT!

  94. This is great to have this full post. This really will be a reference for all the developers. In asp.net also javascript date validation is important, although there exists use of validators also. Here goes one such implementation using javascript:


  95. Thanks for posting this Steve. I am awestruck.

  96. [...] functionality has been built on top of Steven Levithans Date Format class. Our version will extend it a little to allow the use of “Today” and [...]

  97. Hi, if i want to return only true or false (for validation), is possible?

  98. Fantastic script. Just used it in my little hobby project. Thanks!!!

  99. Hi Firnds i have one problem here

    I have one date value with the format of “2009-04-23T06:30:00″ now i want to increase 30 second in this date and return value with the same date format

    for that what can i do ?

    I have done some code for that but this is working for System Date but i need to pass my Own Date Value as an parameter.

    My Code:
    var now = new Date();
    var date1 = now.format(“isoDateTime”);
    now.setMinutes(now.getMinutes() + 30);
    var date2 = now.format(“isoDateTime”);


  100. Simply perfect !

  101. [...] Reference: http://blog.stevenlevithan.com/archives/date-time-format [...]

  102. Thank you so much, that helped me so much; but, for me, “M” worked for months while “m” worked for minutes, also, the “S” suffix didn’t work.

  103. Excelent!!! thanks alot!

  104. Hey man, great job this lib!

  105. Thanks for taking the time to write this!

  106. This is throwing an error:
    var time = now.format(“longTime”, true);

    Also, can’t get any UTC stuff to work.

  107. var time = now.format(“UTC:HH”);

    this returns:

    so it looks like the parsing of that keyword isn’t working..

  108. @burl, I can’t reproduce the problem. (new Date).format("longTime", true) and (new Date).format("UTC:HH") work correctly for me. I just ran the two lines in Firefox and IE after loading Date Format 1.2.3, and got "12:37:20 PM UTC" and "12" in both browsers. What error are you getting? Has your now variable been defined properly?

  109. Thanks for the reply, I did get it to work. FYI I was using a window onload event to have a running clock. I needed to load the JavaScript library at the bottom (best practice anyway) before the closing

    Here’s the code for the clock:

    window.onload = WindowLoad;
    function WindowLoad(event) {
    var now = new Date();
    var day = now.format(“dddd, yyyy-mm-dd”);
    var time = now.format(“UTC:HH:MM:ss”);
    if (document.getElementById) {
    document.getElementById(‘datestamp’).innerHTML = day + ‘ ‘ + time;
    else if (document.layers){
    document.layers.theTime.document.write(day + ‘ ‘ + time);
    setTimeout(“WindowLoad()”, 1000);

    Thanks for this useful library.

  110. Oops – IE7 is not behaving. [Using above code block]

    IE7 displays: Tuessday, 2009-32-07 UTC:09:07:24

    FF 3.5 displays: Tuesday, 2009-07-07 16:32:59

    Maybe the “MM” for minutes is not working for the UTC time and breaking that and also looks like the “mm” is not being picked up either for the month.

  111. @burl, no. The test I mentioned earlier works fine in IE6+ (and probably 5.5 as well). I don’t know what you’re doing in your code, if you’re running a conflicting library, or what may be different in your browser. But I don’t think the problem you describe is in the Date Format library code (which many people are using successfully). If you can isolate a problem in this library (i.e., which line is causing the issue), that would be helpful. Thanks.

  112. Thanks. I think you’re right. The project is using the .NET AJAX framework and Telerik controls which are importing lots of associated javascript files that probably contain the var conflict. bummer.

  113. @burl, you could try using the dateFormat function instead of its Date.prototype.format alias (see the examples at the top of this post), but beyond that, I can’t help with troubleshooting library conflicts. :-(

  114. I got it to work – and you were correct in assuming .NET has a conflict the the Date.prototype.format in its framework library. To avoid any other naming conflicts, I renamed the class util_dateFormat and inlined all of the code in the needed page.

  115. [...] you ever happen to be working on any javascript that uses dates then get your hands on the dateFormat plugin. This handy critter can return a date as a string in a wide range of formats, using the [...]

  116. well done

  117. i was looking for a function that would take a poorly formatted date string that any random user may type in and make an attempt to parse it.

    for example, all of the following would return 1/1/09 (assuming the use of the shortDate format in the script above)

    1/1 -> 01/01/09
    jan 1 -> 01/01/09
    1-1-09 -> 01/01/09

    i don’t think this script is meant to take various formats that users may type and ‘fix’ them. am i missing something? anyone have an alternative script?

  118. Thanks very much for this handy functions – I just started with Javascript and simply could not believe that something so simple has to be coded by hand. You saved me a lot of time.

  119. Hi!

    im trying to use this library in http://cbasites.net/
    it works great in firefox, but in IE(8) it is giving an error in line 38

    if (isNaN(date)) throw SyntaxError(“invalid date”);

    any idea?

    regards, and sorry for the bad english :)

  120. great stuff thanks. i just gave up on datejs and this was exactly what i needed :)

  121. btw, in http://cbasites.net/ I have added an IF IE comment, to use another script for IE… no idea why IE8 handle it that way…

  122. Very helpful. Thank you for posting that.

  123. I plan to include this in an open source environment I’ll be releasing for the first time in Sept.

    Suggestion: “MIT License” is quite vague, and probably doesn’t legally apply the terms of that license to your code. Could you elaborate? :-) At least include a link to the MIT document!

  124. Fantastic tool!! Thanks for sharing this.

  125. ive got a script below:

    var m = document.lastModified; var p = m.length-8; var d = m.substring(p, 0);

    // End –>

    how to i change the date to be of dd/mm/yy format instead of mm/dd/yy what it is in now? ive tried the text above but it doesnt work

  126. There isn’t an easy way to format the document.lastModified() function, nothing in the protocol anyway, this website has a good script that implements it well


  127. Thanks for the very useful script! It’s great to be able to do this kind of intuitive formatting without having to deal with all the bugs and quirks of Datejs.

  128. I think this is a beautiful script. Was wondering if it was possible (and if so, how?) to convert something like 2009-09-11T11:30:00-07:00 to September 11, 2009 11:30am

  129. Hi Steven,

    I am a noob when it comes to using JavaScript, so this may seem like a very basic question…. but here goes.

    I’m trying to figure out how to convert this long form string into just the time part (HH:MM AM or PM: 2009-09-18 15:45:15

    The “s.at” below is the variable that contains the string to be converted. How would I call your function and where should your function go (external, header or embedded in the script from which the line below was taken)?

    CODE SNIP: html += “”+s.at+” “+s.by+” – “+s.title+”";

    Code was provided by YES.Com’s API

  130. Here are the german internationalizations:

    dayNames: [
    "So", "Mo", "Di", "Mi", "Do", "Fr", "Sa",
    "Sonntag", "Montag", "Dienstag", "Mittwoch", "Donnerstag", "Freitag", "Samastag"
    monthNames: [
    "Jan", "Feb", "Mär", "Apr", "Mai", "Jun", "Jul", "Aug", "Sep", "Okt", "Nov", "Dez",
    "Januar", "Februar", "März", "April", "Mai", "Juni", "Juli", "August", "September", "Oktober", "November", "Dezember"

  131. date.dateFormat(“H:M:s”);


    but the “10″ correpond to octobre and not to the hours … why ?

  132. [...] 没有评论 分类: MemorySnippet 发表日期:2009 十一月 5th ,11:03 上午 link:http://blog.stevenlevithan.com/archives/date-time-formatvar now = new Date(); now.format("m/dd/yy"); // Returns, e.g., 6/09/07 // Can also be used [...]

  133. gracias, desde Mexico !!!! se sirvio de mucho

  134. cool man, im going to use into my website in the next realease cool job :)

  135. Hi. Thank you so much for your work on this set of functions. It’s really very excellent and useful. You’ve saved me a lot of time.

    In Firefox your function throws a syntax error with the input in the form “mm-dd-yyyy”. In Chrome and I’m guessing Safari, this works fine.

    This is a pretty nasty fix but it works. (at line 36):

    EDIT: It’s not letting me post the code, so here it is

    It replaces the “-”s with “/”s. It works for my purposes, but I don’t know if it would be good in general.

    Again, thank you very much. Is leaving your license/name heading in the file sufficient for crediting you?

  136. Steve,

    Excellent work! Got one question; I am not too familar with the MIT License; but can I add this to my commercial application? Anything else I needed to add to my application to meet the MIT license for using this? Many Thanks!

    Ofcourse, I will include the follow comments:

    * Date Format 1.2.3
    * (c) 2007-2009 Steven Levithan
    * MIT license
    * Includes enhancements by Scott Trenda
    * and Kris Kowal
    * Accepts a date, a mask, or a date and a mask.
    * Returns a formatted version of the given date.
    * The date defaults to the current date/time.
    * The mask defaults to dateFormat.masks.default.

  137. @skyrun, yeah, this library is not designed to parse date strings; it formats dates as strings. It’s parsing responsibilities are merely passed off to the native Date constructor methods (see https://developer.mozilla.org/en/Core_JavaScript_1.5_Reference/Global_Objects/Date/parse ).

    @Luciano A. Ferrer, what is the error? Is it saying you provided an invalid date? :) Keep in mind that, as noted above, this library does not have robust date parsing (which is simply passed off to whatever the browser supports natively). Generally, it’s safer to provide an actual date object to the function; not a date-like string.

    @Liam Breck, whatever. It’s well understood that an unqualified “MIT License” refers exclusively to the “X11 license” (if you prefer the less common and less recognizable name). See http://en.wikipedia.org/wiki/MIT_License , etc.

    @fuultier, thanks for that!

    @Tyler, see my comments to skyrun and Luciano A. Ferrer above. This is not (currently, anyway) a date parsing library, beyond a few basic formats that can be handled by the native Date constructors cross-browser. And yes, including the credits in the source file is sufficient.

    @Sam, yes, including those credits is enough. :)

    Thanks, all!

  138. Brillant!
    some simple things are always brillant. I needed to get the date in the UTC format et voila!
    Great Job


  139. Steve,

    Kudos on the code; I’ve learned quite a bit perusing through and deconstructing it.

    I’m using dateFormat for some code that talks with Google’s GData services, Google Calendar in particular. Google’s API barfs when the offset is -0500 but works fine with -05:00 (see the start-max and start-min params in the URL):

    http://j.mp/6r7mdo (correct)
    http://j.mp/59kLcZ (error)

    Consequently I’ve added a new flag:

    O: (o > 0 ? “-” : “+”) + pad(Math.floor(Math.abs(o) / 60), 2) + “:” + pad(Math.abs(o) % 60, 2)


  140. Hi!

    I did some changes in the source code to allow multi i18n.

    The default culture is english. If you want to add more culture, add a JS file with the object’s array filled.

    How can I send you the code for proposal?


  141. @Vincent Bergeron, you could email me (email address on the About page), but probably a better route would be to use a service like pastebin and link to the code here. That way other people can see/use the code before I add it or if I decide not to include it in the library. Thanks!

  142. @Vincent Bergeron: I’d also be interested in any i18n changes, so it would be great if you could toss that up in pastebin.


  143. Good day,

    I’ll appreciate it if somebody can assist with the following query…

    Using the dateFormat javascript command in IDE, I manage to successfully select most of the date links when recording and playback. However, in some instances we have date links which have exactly the same dates, but each link refers to different pages. (i.e. different attached emails).

    Using the HTML tags I could identify that eg. Date 1 = “25 January 20101″ and Date 2 = “25 January 20102″, but I battle to find the correct dateFormat which will allow me to select the required Date 1 or Date 2 when the actual dates are the same.

    The following script will always select the first occurrence (Date 1):

    store|javascript{dateFormat(dateTodayPlusDays(0),”dd mmmm yyyy”)}|aLink


  144. I’ve created a Hungarian and a Hebrew translation. You can see them here:

  145. how can i used it
    onblur=dateFormat(this,shortdate,utc) ?

  146. Awesome code – thank you!

    How can I modify to include the Quarter (i.e. Q1 = Jan, Feb and Mar, Q2 = Apr, May, Jun, etc).

    I want to be able to do a format mask to show Q1 – 2009, Q2 – 2009, etc or the long way: Quarter 1 – 2009, Quarter 2 – 2009, etc.

    Please help.

  147. @flocsy, thanks for sharing that.

    @James, to add support for quarters (digit 1–4, via the mask Q), change the [LloSZ] character class in the token regex to [LloSZQ], and add Q: Math.ceil((m + 1) / 3) to the flags object.

    After that, you should be able to use something like dateFormat("'Q'Q - yyyy") or dateFormat("'Quarter' Q - yyyy").

  148. I wonder how do I go from 12 hours format to 24 hour format

    eg 10:00 AM to make this 10:00:00


  149. Awesome!! It helped me a lot to convert time in different locales to GMT

  150. saludos, el otro estube buscando como formatear la salida de fechas en javascript, y se me ocurio migrar la función http://www.devtics.com.mx/wp/index.php/238-funcion-date-para-formatear-salida-de-fechas-en-javascript/ date() de PHP a JavaScript, y aquí se las dejo, se maneja exactamente = que date en php :) espero le sirva , me faltaron migrar algunos parametros, ya que se me complicaron un poco o bien no entendia bien como obtenerlos o no entendia en que se usaba, pero esta un 70% migrada y se puden usar los formatos mas usuales

  151. [...] en extension, der kan formatere en dato i alle mulige formater. Jeg fandt hvad jeg ledte efter på Steven Levithans blog, hvor man også kan downloade koden. Steven Levithans udvidelse til Date objektet er ret vildt. Man [...]

  152. oh, thanks. realy usefull thing.

  153. I have three dates like date 1,date 2,date 3(Format-dd/mm/yyyy).
    In that all dates can be entered between nov to feb month.
    date 1 and date 2 should have 1 week gap between them no matter of date1 should be greater than date 2.but 1 week can should be dere.
    If i enter 1 row for 2010 year again i should not enter for 2010.

    Can anyone say the validation for this.I am workin in VB.NET

    Thanks in Advance.

  154. Hi,

    seems great and extensible code, but since I am just a copy-paste programmer, please, could someone help me implement this function with simple HTML form.
    I’d like to check & alter user’s input into textfield, so to format it corectly for insertion in database, like this:

    (ok, this sample DOES NOT work)
    But question is if this function can be used to correct user input like in my case?

  155. If I need a date is format say May 12, 2010. Do I have to do something lke this:

    exercise 1

    var dt = new Date();
    //var month = currentTime.getMonth()+1;
    //var day = currentTime.getDate();
    //var year = currentTime.getFullYear();
    dateFormat(dt, “mmm, dS, yyyy”);
    document.write(month +”/” +day +”/” +year);

    Thanks for the help

  156. [...] javascript date format [...]

  157. Hi,
    it’s a pleasure to use your library, simple, fast and well done!

    I introduced a little variant, to handle iso-8601, handled by JAXB, the library I’m using to read and write JSON objects.

    When you use the ‘o’ switch, you rightly writes the time zone like ‘+0200′, however iso-8601 uses ‘:’ character, to separate hours to minutes, like ‘+02:02′

    this is what I change:
    o:(o > 0 ? “-” : “+”) + (pad(Math.floor(Math.abs(o) / 60),2)+”:”+pad(Math.abs(o) % 60,2)),

    Thank’s a lot again!
    Ciao, Davide.

  158. Thanks for this nice script.
    It would be perfect if it has a function to parse a date for a given mask.

  159. [...] July 9, 2010 by Roy Jin Leave a Comment Link [http://blog.stevenlevithan.com/archives/date-time-format] [...]

  160. very helpful to find the javascript date time…

  161. Good work. Thanks!!!

  162. Hello, I wanted to report a bug fix to this library.

    I noticed that if a text field had a value already it was showing the wrong year.

    The reason for this is that the function “getYear()” was used in two places.

    Changing this to “getFullYear()” fixed the issue.

  163. Hi,

    It seems there is a problem in IE7 — maybe I’m doing something wrong, but the script causes a complete javascript failure:

    “Exception thrown and not caught”
    About 23 lines down from “var dateFormat = function(){“….

    you have:
    “if (isNaN(date)) throw SyntaxError(“invalid date”);”

    Should the function itself be wrapped in a try/catch?


  164. Hmmm, it seems IE7 trips over this:

    var date = new Date(Fri Jul 23 23:21:11 +0000 2010);

    var dateString = date.format(“h:MM TT mmm dS”);

    dateString becomes : 12:NaN PM NaN


  165. Thank you. Cool stuff!!!

  166. It’s wonderfull!!!! thanks a lot….

  167. Very nice piece of code thanks

  168. This is superb. Thanks a million.

  169. [...] next one, I found was this found here. The idea here is to use String’s replace method with a function for each possible token. And [...]

  170. Thanx man!

  171. [...] basado en @Anywhere. Está creado usando HTML, CSS, Javascript y jQuery. Incorporé los plugins Date Format y timeago para mostrar las fechas, pero no son imprescindibles. (¿Hay una forma más simple de [...]

  172. @trevor I had the same problem.

    I was getting a date back from our servers as yyyy-mm-dd. When I passed that string to dateFormat() it threw an exception in IE only, not in any other browser.

    To correct that I changed my call to this:
    dateFormat(strDate.replace(/-/g, ‘/’), “mm-dd-yyyy” );

    Problem solved.

  173. [...] found a little js library, date.format.js, that had some nice features to it. It’s a regular js file, that modifies the Date [...]

  174. @Chris

    I was having the same problems as @trevor and some others, mostly due to the fact that this script relies on the default Date parsing, which IE must handle a bit differently than other browsers.

    I was trying to take the date that was returned from a Blogger JSON feed, but was unable to get the formatting to work in IE. I used your code:

    dateFormat(strDate.replace(/-/g, ‘/’), “fullDate”);

    But I also had to add a .substr(0,9) to isolate YYYY/MM/DD from the rest of the Blogger date formatting. As mentioned, this script is meant for dealing with Date objects not strings, so my method is a bit of a messy hack, but it works for what I need it for.

    Once I got the string formatted properly, Steve’s formatting script was perfect. Thanks for that Steve!

  175. I’ve created a jQuery plugin (inspired by this code) for localizing dates and times. It retrieves date, time, and time zone information from the HTML5 `time` element’s `datetime` attribute, and updates both the displayed text and the value of the `datetime` attribute in accordance with the specified format string.

    At its simplest, localizing date and times using the plugin takes just a few characters.


    The plugin is highly flexible and supports non-English languages. The project lives on Bitbucket: http://bitbucket.org/davidchambers/jquery.localize.

  176. Awesome – exactly what I was after. Saved me ages writing my own, cheers!


  177. Thanks, man, awesome library. You may have more formatting options than PHP’s date()!

  178. I am running into an issue where having the client computer in a timezone that’s UTC/GMT offset includes minutes such as Kathmandu (GMT +5:45) causes an unexpected result. Here’s the usage:

    var msTime = 1290579300033;
    var date = new Date(msTime);

    var dateFormatString = “mm/dd/yyyy HH:MM:ss”;
    var result = date.format(dateFormatString);

    // Actual result = 11/24/2010 06:15:00 GMT
    // Expected result = 11/24/2010 06:00:00 GMT

  179. Great library, have been using it for a while and found it very useful. Thanks for sharing!

  180. I withdraw my comment. It turns out the issue was occurring elsewhere.

  181. If you are accustomed with Java, try it


    It uses the same syntax as used by Java SimpleDateFormat

  182. I found this date plugin for jQuery…


    It’s got some pretty cool stuff I haven’t seen elsewhere.

  183. Hi,
    As I want to use this kind of date picker (http://www.projectcodegen.com/JQueryDateTimePicker.aspx),I know Its mixup of jquery + java script but when i tried to give its format than it is showing me random result in textbox so please help me.I am using it with below syntax
    $(‘#mydatepicker’).datetimepicker({‘DateFormat: ‘dd/mm/yyyy hh:MM tt’});

    With Other all the formats it is working fine like mm/dd/yyyy ….etc. but when i give dd/mm/yyyy hh:MM tt format than only its performing random result so plz give me reply as soon as possible….Thanks In Advance.

  184. [...] JavaScript Date Format (stevenlevithan.com) [...]

  185. I am using this with Firefox 3.x and Chrome without issue, but when I try to run it in Safari or Mobile Safari (iPad) I get the following:

    JavaScript Error on Line 38
    SyntaxError: invalid date

    The format I am passing in is like this: “2011-01-15T14:55:14-08:00″.

    I tried using the trick of subbing ‘-’ for ‘/’, but that didn’t seem to help…

    Any suggestions on how to fix?

  186. [...] JavaScript Date Format (stevenlevithan.com) [...]

  187. [...] make Twitter and Facebook date parsing a little easier. One of them is timeago and the other one is dateFormat. Although I had to put a condition to check if its IE as the dateFormat function was not playing [...]

  188. [...] dateformat.js – takes care of correct dateformat [...]

  189. I used your dateformat in jquery durationpicker plugin.

  190. I came across a brand new JavaScript library called jPaq which provides a function that closely emulates PHP’s date function. Documentation for this function can be found here: http://jpaq.org/documentation/Date.prototype.format%28%29/1.0/.

  191. Works perfectly! Used in the CodeCharge Studio framework.

  192. I should add that I too had to use the

    dateFormat(strDate.replace(/-/g, ‘/’), “mm-dd-yyyy” );

    workaround for IE8 and FF3.

  193. Very helpful and easy to use. Much obliged to ya!

  194. [...]             },             formatDate : function(date){  //note: dependency on dataTimeParser.js                return new Date(parseInt(date.substr(6))).format(“d mmm”, [...]

  195. It’s all good, but would be nice to have method for parsing all these formats back into Date object.
    Because, for instance, i have filter on web page, that stores filter control values in text form (for sending via URL, etc). I need some specific format for using in DB2 SQL function, but this format is not recognized by standard Date.parse method! So, now I need to invent something…

  196. This is awesome! This should be included in the official Javascript language IMO. Very helpful. Thanks!


  197. Thank you very much!

  198. Great article. I wanted to point out that your example and reference table are backwards for minutes and months.

    m and mm are minutes

    M and MM are months

  199. [...] After you go through the code a bit, you’ll notice that I’ve abstracted some functionality into the lib folder by following separation of concerns. Part of my implementation includes a great little javascript library by Stephen Levithan found here [...]

  200. Very nice. Thanks.

  201. what r u mention in this blog all are wrong

  202. your right Ajay Verma… this blog all wrong!

  203. Hello Steven,

    I used
    xaxis_value = dateFormat(‘Apr 1 2011′, ‘yyyy-mmm’);
    Output: April 1st

    But it doesn’t work. Can you guide me how to correct?


  204. Hello
    Very interesting Steven.

    I don’t want to use it in a separate file but I want to include it in my library and customize it. Is there any restriction? I’m familiar to license terms.

    I’m waiting your answer.


  205. I’m confused, how do you get this to output to an html element on screen. Nothing seems to be formatted when I use this script:

    var d = new Date();
    d.format(“mmmm dS, yyyy – h:MM TT”);

  206. Mike – you’re confused here by what the format() method is doing. It doesn’t modify the underlying Date object at all, it just processes the Date object’s properties into the format string. If you want to do something with the formatted string, you need to do that with the result of the method call. Like this:
    document.getElementById(“time”).innerHTML = (new Date).format(“mmmm dS, yyyy – h:MM TT”);

    Steve – I found a bug in the L processing. It’s small and likely insignificant, but incorrect nonetheless. If L < 100, then it will be output literally to the result, but without any sort of leading zeros, altering its value in the decimal place. So 99ms and 990ms will end up showing as the same L value. If you want L to always be 2 decimal places, then you need to use pad(Math.round(L / 10)). Personally I’d prefer that L stand for “milliseconds with no trailing zeros”, in which case you’d just use String(L).replace(/0+$/, “”). Your choice, but I’d recommend fixing it one way or the other before long.

    Oh, and I know it’s been over two years since it was released, but congratulations on your O’Reilly book! :) And I never noticed the “Powered by Vodka • Red Bull” links in the bottom of your site – I’m a Red Bull fiend as well. :D

  207. This prototype is really nice, Steven. Thanks for posting it. I’ll be using it shortly on this lottery page: http://www.projo.com/lottery

  208. Hi can any convert the date into this format…

    CYYD to mm/dd

    CYMD is century year month date

    Example: 1,110601 to 6/01 //(jun 1st)

  209. I need a code for “yymmdd” type dates..help me

  210. I found your code today – great! Just what i needed.

    However, it appears that the input date parameter does not like having a date ordinal suffix (st, nd, rd, or th).

    This works: dateFormat(‘Sat, Jun 11, 2011 10:30 am, EDT’,'mmm-dd-yyyy HH:MMTT’);

    This does not work: dateFormat(‘Sat, Jun 11th, 2011 10:30 am, EDT’,'mmm-dd-yyyy HH:MMTT’);


    While i can strip the ordinal sufix out, it would be nice not to have to.

  211. Hi,

    It’s great to finally find a workable JavaScript lib for dates. However, I seem to be having some problems with the format: dd/mm/yyyy, it appears to format it as mm/dd/yyyy. I have written the following simple test, which if you enter say 10/02/2011 it comes out as 02/10/2011. I guess I’m just misunderstanding something.

    Any advice would be welcome.



    <script language=”javascript” type=”text/javascript” src=”date.format.js”></script>
    <script language=”javascript” type=”text/javascript”>
    function CheckDate(ctrl, format)
    var dte = dateFormat(ctrl.value, format);
    if (dte == ctrl.value)
    writeResponse(“Match: dte:” + dte + “, ctrl:” + ctrl.value);
    writeResponse(“Unmatched: dte:” + dte + “, ctrl:” + ctrl.value);
    catch (e) { writeResponse(“Error:=” + e.Description); }

    function writeResponse(msg) { document.getElementById(“response”).innerHTML = msg; }
    <form id=”form1″>
    <input type=”text” class=”date” onkeyup=”CheckDate(this, ‘dd/mm/yyyy’);” /><span> (dd/mm/yyyy)</span>
    <div><span id=”response”></span></div>

  212. Hi,

    When I test using the test harness above in IE, with a date such as 21/11/1968 comes back as 11/09/1969.

    I have tested it using IE9, IE8 (IE9 compatibility) and IE7 (IE9 compatibility), and in each case, 11/09/1969 is returned.

    Does this mean that the script isn’t compatible with IE?


    P.S. – I have found that if I instantiate a new Date object using the dte variable in the constructor, and then call the .format(format) method, I can get the date back to my desired format in Firefox.

  213. Hi,

    To add to my previous comment, the date 21/11/1968 also formats to 11/09/1969 in both Firefox and Opera as well.

    In Chrome I get a ‘SyntaxError: invalid date’ error. It is difficult to see what the problem is with Safari, but I suspect that it is encountering the same issue as Chrome.

    Perhaps I’m using the library incorrectly? I’d be grateful for some advice.



  214. Thanks for the code dude.
    This was really helpful for me.

  215. Thanks!! it helped!!

  216. A million THANKS !!!!!!!

  217. Hi,
    Thanks in advance for your time, please solve my following issue if possible…
    I have 2 files… 1 is html which is time counter and second one is showing registered user date and time… example : user registered with us july 16, 2011 20:00:00 and after 10 days they can upload or download free files — in member tpl file showing date in this format {$data[0].registration_date|date_format:”%d/%m/%Y”}, but in html counter file is like :
    var refDate = new Date(“july 16, 2011 20:00:00″); // start date;
    if I write {$data[0].registration_date|date_format:”%d/%m/%Y”} in start date there is error…. and result NnNn etc.

    if you like I can send you files for further ….

    Thanks again for your time and sorry about my English if any mistake…

  218. Very nice script man, saved me a lot of hassel. Is it ok if i attach a link to this post from my blog

  219. Very nice function! Very well-rounded. You have made my life a lot easier. Thanks!

  220. Awesome script man. It does exactly as I wanted it. Thanks alot dude. :)

  221. var DateTime = {
    ShortMonths: new Array(“Jan”, “Feb”, “Mar”, “Apr”, “May”, “Jun”, “Jul”, “Aug”, “Sep”, “Oct”, “Nov”, “Dec”),
    LongMonths: new Array(“January”, “February”, “March”, “April”, “May”, “June”, “July”, “August”, “September”, “October”, “November”, “December”),
    ShortDays: new Array(“Sun”, “Mon”, “Tue”, “Wed”, “Thu”, “Fri”, “Sat”),
    LongDays: new Array(“Sunday”, “Monday”, “Tuesday”, “Wednesday”, “Thursday”, “Friday”, “Saturday”),
    SuperScript: function (day) {
    if ((/^(1|21|31)$/).test(day))
    return “st”;
    else if ((/^(2|22)$/).test(day))
    return “nd”;
    else if ((/^(3|23)$/).test(day))
    return “rd”;
    return “th”;
    FormatDate: function (_d, regexp) {
    regexp = regexp.replace(/y/g, “g”);
    regexp = regexp.replace(/M/g, “k”);
    regexp = regexp.replace(/d/g, “q”);
    regexp = regexp.replace(/h/g, “x”);
    regexp = regexp.replace(/m/g, “z”);

    var dddd = this.LongDays[_d.getDay()];
    var ddd = this.ShortDays[_d.getDay()];
    var dd = ((_d.getDate() < 10) ? "0" : "") + _d.getDate();
    var d = _d.getDate();
    var a = this.SuperScript(_d.getDate());
    var MMMM = this.LongMonths[_d.getMonth()];
    var MMM = this.ShortMonths[_d.getMonth()];
    var MM = ((_d.getMonth() < 10) ? "0" : "") + _d.getMonth();
    var M = _d.getMonth();
    var yyyy = _d.getFullYear();
    var yy = yyyy.toString().substring(2);

    regexp = regexp.replace("qqqq", dddd);
    regexp = regexp.replace("qqq", ddd);
    regexp = regexp.replace("qq", dd);
    regexp = regexp.replace("q", d);
    regexp = regexp.replace("a", a);
    regexp = regexp.replace("kkkk", MMMM);
    regexp = regexp.replace("kkk", MMM);
    regexp = regexp.replace("kk", MM);
    regexp = regexp.replace("k", M);
    regexp = regexp.replace("gggg", yyyy);
    regexp = regexp.replace("gg", yy);

    return regexp;

  222. opps. you will have to put the following line above the line
    regexp = regexp.replace(“qqqq”, dddd);

    regexp = regexp.replace(“a”, a);

  223. Awesome this script saved me a ton of time.

  224. Great contribution! Is there a closure based implementation? We’re refactoring a legacy app and one of our goals is to minimize attaching objects to the global namespace.

  225. Thank you for your script. It is amazing that there are no built-in JavaScript functions.

  226. I don’t see a PayPal ‘donate’ button. This script saved me tons of time. Thanks a lot.

  227. Thanks, Thanks. :)

  228. Great code. Small and pluggable.

  229. thx, save me a lot of time.

  230. Hello Everyone,
    We can use Date () object to manipulate dates in java script. Whenever we want to access current date of the system or want to set new date in java script then we can use appropriate java script method of date function. In this demonstration we learn how to work with function of date object………….
    Please check out this link for more details ……..

    Thanks !!!

  231. Hi,
    Thanx for your script. Its really helpful, i am using this script from 2008 :)

  232. Thank you. Great script, great documentation. Thanks a lot.

  233. Steven . . .

    Thank you so much for this. I have been wrestling with formatting dates in JavaScript for some time. This function is extremely helpful.

    Just one issue that I found (frankly for most needs its a non-issue). When attempting to format a date that has a three digit year to four digits, I would expect the leading zero in the year.

    Example: var sDateString = dateFormat(new Date(266,2,3),’mm/dd/yyyy’); i would expect it to return ’03/03/0266′. Instead it returns ’03/03/266′. (JavaScript months are zero based, whether I like it or not . . . and I don’t.)

    Anyway . . . this is, undoubtedly, a non-issue for most developers. I just thought you might like to know for completeness sake.

    Thanks again for an awesome piece of code!


  234. Good guy! From Brazil!

  235. Thanks, Thanks.

    Get free valid nod32 username paswwords by visiting my blog. Please follow my blog if you interest.

  236. Thanks. Saved me lot of time.

  237. La migliore informazione essenziale è questo, che si cerca di fare molto bene in avvicinamento per quel corpo senza fissa dimora e la loro mano. Sono così ispirato a tale proposito, dopo aver letto questa tua articoli utili scritti e le vostre opinioni anche che è così attraente per fare qualcosa per quei

  238. Please, _please_ don’t modify built-ins “for convienence”. This doesn’t serve anything and leads to conflicts, which people then complain about.

  239. Steve
    If my input string is “19/1/2010″ as in European format, it does not give me the desired result. The 19 is converted to the month 7 and the date is parsed as 7/1/2010. Any suggestions?

  240. @Steve:
    You are the hero of the Day,
    thank you very much for your work!
    If you’d know of how much time and problems you saved me :)

    I didn’t think it would be such a pain in the a$$ getting a formated UTC Output in JS, but now it is no problem anymore :)

    greets from Italy

  241. The isoDate doesn’t seem to be consistent.
    If I write as follow,
    var date = new Date();

    It prints the date of yesterday(not today).

  242. Hello there,

    Thank you for your script! It really helped me today :-)

    I am putting it in my default script list for my projects!

  243. Strange, milliseconds (l and L) work in Firefox and Chrome, but not in IE (9).

    dateFormat(new Date(), “yyyy/mm/dd hh:MM:ss L l”) + ” getMilliseconds(): ” + new Date().getMilliseconds();

    2012/01/27 02:52:33 00 000 getMilliseconds(): 545

    both l and L always return 0

  244. [...] os dados do MongoDB e trabalhar com eles diretamente no JavaScript visando formatação recomendo este link, que contém uma descrição de como realizar tais manipulações. O mesmo vale para operações [...]

  245. Fantastic code!!

    Great job.

    I love it when a plan comes together. And this was well done!


  246. saved my day ! thx

  247. [...] But JavaScript does not have a DateFormat object you might be use to from other languages. I’ve found one that looks rather good here. [...]

  248. Need to clarify.Code examples or methods provided on this article will work as a part of the web page. But if you want to use it in standalone JS file(for example to execute as part of BATCH job) – good luck Charlie.

  249. [...] parte positiva es que es fácil encontrar librerías para ello, algunas muy ligeras, como date.format.js, y otras más completas, como [...]

  250. Thanks. I just made a code like this:
    return time.getFullYear().toString() + ‘-’ +
    ((time.getMonth()+1) < 11 ? ('0' + (time.getMonth()+1)) : time.getMonth()+1 )+ '-' +
    ((time.getDay()) < 11 ? ('0' + (time.getDay())) : time.getDay() ) + ' ' +
    ((time.getHours()) < 11 ? ('0' + (time.getHours())) : time.getHours() ) + ':' +
    ((time.getMinutes()) < 11 ? ('0' + (time.getMinutes())) : time.getMinutes() ) + ':' +
    ((time.getSeconds()) < 11 ? ('0' + (time.getSeconds())) : time.getSeconds() );


    Good job.

  251. I have some dates in json file that are in isoDateTime format (i.e. 2007-08-10T11:56:06). In my javascript I am formatting these dates using the following:
    dateFormat(new Date(data._source.submissionTime),”longDate”);

    data._source.submissionTime resolves to date you see above (2007-08-10T11:56:06)

    Firefox and Chrome handle this just fine, however IE 8 is choking on the following line in your script and complaining that exception is not caught:

    if (isNaN(date)) throw SyntaxError(“invalid date”);

    Any thoughts on why IE is unable to handle this?

  252. The other thing I forgot mention above is that if do replace the hyphens with slash (as was suggested in previous posts), then IE works by Firefox and Chrome break :-)

  253. hey guys ‘mm’ is taking as minute and ‘MM’ is taking month
    let me know correct one
    current I have used as

  254. Just written something similar, noticed a complicated looking zero pad function up there, here’s the one I just wrote:

    function zeroPad(number) {
    if (number < 10) {
    return '0' + number;
    else {
    return '' + number;

  255. Hi guys… JsSimpleDateFormat can parse the formatted string back to the Date Object


    Two ways functions.. Could the others do this?

  256. [...] For the dateFormat() I’ve used Date Format 1.2.3. [...]

  257. [...] For the dateFormat() I’ve used Date Format 1.2.3. [...]

  258. [...] : this is a little script by Steven Levithan that adds a format function to the date object so you can easily convert javascript dates to [...]

  259. [...] as nice to print out various formats as it is with other server-side languages. For this reason there-are-many-functions available in the wild. Tagged: jquery /* * * CONFIGURATION [...]

  260. var now = new Date();


    Not working in javascript

  261. [...] use a DateFormatter to convert it to/from text in Java. For JavaScript, using a library such as Date Format will help you render it as appropriate on the page (for example with something like new Date(val * [...]

  262. [...] But JavaScript does not have a DateFormat object you might be use to from other languages. I’ve found one that looks rather good here. [...]

  263. Steven, thank You very much!
    Now I dont have any problem with date/time formatting in javascript!
    Best regards, Vasily.

  264. [...] JavaScript Date Format. Share this:TwitterFacebookLike this:LikeBe the first to like this. [...]

  265. Hi Steve
    Great work …thanks… :)

  266. Ciao,
    potresti indicare anche l’html che va inserito per visualizzare l’orologio?

  267. Cool! Very useful extension!

  268. I’m trying to subtract one time from another and cannot seem to get it to display.

    Here is what I’m currently trying:

    var end = dateFormat(event.end, “isoTime”);
    var start = dateFormat(event.start, “isoTime”);
    var total = (end – start);

  269. Thank you so much for this awesome script. Really valuable input!

  270. First, I want to thank you for creating this library. I have been using your script without any problems on FF 3+. However, I have run into some difficulties on Chrome and Safari. I create a new date using an input like this one:

    var localDate = new Date(“2012-09-05T09:30″);

    and latter on my code I use the UTC mask


    on FF i get this:

    on Chrome 21 and Safari 6 I get this:

    Any ideas as why this is happening?

  271. [...] Steven Levithan’s date format to display things makes formatting really quite simple – all you need to do is call the [...]

  272. following is code to remove ordinal of date IT is running successfully:

    import java.text.DateFormat;
    import java.text.ParseException;
    import java.text.SimpleDateFormat;
    import java.util.Date;
    import java.util.regex.Pattern;
    import java.util.regex.Matcher;

    public class patrn {

    private static String deleteOrdinal(String dateString) {
    Pattern p1 = Pattern.compile(“([0-9]+)(st|nd|rd|th)”);
    Matcher m = p1.matcher(dateString);
    while (m.find()) {
    dateString = dateString.replaceAll(Matcher.quoteReplacement(m.group(0)), m.group(1));
    return dateString;

    public static void main(String[] args) {

    String dateString=”August 21st, 2012″;
    SimpleDateFormat sdf = new SimpleDateFormat(“MMMM dd, yyyy”);
    Date emp1joinDate = null;
    try {
    } catch (ParseException e) {
    // TODO Auto-generated catch block



  273. [...] http://blog.stevenlevithan.com/archives/date-time-format [...]

  274. Excellent! Just when I was getting at the huge mess in my code … now with your library it’s clean 1 line of code!

    Keep up the good work!

  275. simply superb, great work

  276. // In case anyone ever need czech i18n strings
    dateFormat.i18n = {
    dayNames: ["Ne", "Po", "Út", "St", "Čt", "Pá", "So", "Neděle", "Pondělí", "Úterý", "Středa", "Čtvrtek", "Pátek", "Sobota"],
    monthNames: ["Led", "Únr", "Bře", "Dub", "Kvě", "Čvn", "Čvc", "Srp", "Zář", "Říj", "Lis", "Pro", "Leden", "Únor", "Březen", "Duben", "Květen", "Červen", "Červenec", "Srpen", "Září", "Říjen", "Listopad", "Prosinec"]

  277. Nice

  278. Great script!

  279. Thanks for great script ! It help me very much.

  280. Another big thank you for putting this together. Something this clean and useful should be built into core javascript.

  281. I had one little issue when formatting the date output with padded hours, minutes, seconds, and AM and PM. If a number did need to be padded it actually ended up being repeated. For example if I specified the form seconds format to be ss and the time was currently 9 seconds, I would get 99 for the second count. If I formatted with the time TT asking for AM or PM, would get AA in the morning and PP at night.

    I had to make one little change to the regex in the first line of the dateFormat function to fix this issue.

    Here is the original
    var dateFormat = function () {
    var token = /d{1,4}|m{1,4}|yy(?:yy)?|([HhMsTt])\1?|[LloSZ]|”[^"]*”|’[^']*’/g,

    Here is the change I made:
    var dateFormat = function () {
    var token = /d{1,4}|m{1,4}|yy(?:yy)?|([HhMsTt]{1,2})\1?|[LloSZ]|”[^"]*”|’[^']*’/g,

    I just added the {1,2} after the [HhMsTt] and now it works great!
    Thanks so much for a great date formatting package!

  282. You’re awesome. This helps me a lot!!!! Thank!!

  283. [...] not sure the proper way to do this, but I found a solution. I just downloaded date.format.js from JavaScript Date Format. And I modified my JavaScript function to be: [...]

  284. Hi im using your code on a SharePoint site but for some reason i could not add the file using the script tag of a web part when i do that and tried to use any format i just got in response a lot of weird characters, i copy all the code and append it at the end of another js file and it works as normal, i tried the file using jsfiddler and works just good have you hear of any problems while using your file on SharePoint before?

  285. I have found and corrected a defect in the code as of today. When running this code in the Firefox v 20.0 Scratchpad, I ran into the following exception:

    Exception: dF.masks is undefined

    I corrected this issue by changing the line:
    var dF = dateFormat;
    var dF = this.dateFormat;

    -=> Gregg <=-

  286. [...] date.format.js – a small date/time parsing and formatting library that works quite well.  I also hear that moment.js is really good, but have not used it.  JS’s support for Dates is pretty bad so these libraries help ease the pain, considerably. [...]

  287. Superb, thanks.

  288. Awesome work man! thank you!

  289. Thank you very much, was great!! :) :)
    the perfect javascript for my job :D

  290. [...] (not even jQuery or Underscore), which is pretty impressive in itself. I’ll also be importing the DateFormat library for making the timestamps on my blog posts look nice. The blog.js file will harbor my [...]

  291. Thanks for this, but I think there’s a bug with millisecond display when running on Firefox 20.0 on OS X 10.6.8 (and probably other platforms).

    The problem is line 39:

    date = date ? new Date(date) : new Date;

    It seems that this sets the number of milliseconds to zero on the created Date. Looking at the Date() doc, the constructor can’t take a Date as an argument, but a string, so it converts the initial Date to a string using Date.toString(), which doesn’t include milliseconds. The new Date is then built without milliseconds.

    Commenting out the line is a quick fix.

    Thanks again,

  292. You save me 1000000000 hours of works! Thanks

  293. High five!. Thanks!

  294. Please Help me

    var txt = 04/04;
    dateFormat(var, “dd/mm/yyyy”);

    why result : 04/04/2001
    should : 04/04/2013


  295. You saved me quite a bit of time with this library. Thanks!

  296. I am trying to format a date that is 5 hours back (Unix TS = 1378470618) converted shows Fri, 06 Sep 2013 12:30:18 GMT (5 hrs back)

    When I use the date formatter like :

    dateFormat(start, “yyyymmddhhMM”) where start is 1378470618, the result shows Start Formatted 197001160554
    end = now timestamp and it formats -> End Formatted 201309060130

    Any idea why?

  297. Many thanks for the awesome utility sir…

  298. Thank you for this Absolutely fabulous little script…

  299. [...] $this->getInput($this->keyEditTimeFmt, $this->keyEditTimeFmt, $wc_timeformat); $fmtInfo = ‘ [?]‘; return ‘ ‘ . $labelDate . $fmtInfo . ‘‘ . $inputDate . [...]

  300. Thank your for this fine component. It saved me tons of time as I am just starting to venture into Javascript…

    Greetings from Berlin,


  301. Thanks a lot!! Really helped in implementing a required functionality!!

  302. Great Work! Honestly is quick, simple and do its works perfectly. Thanks!

  303. Hi

    *** Possible Bug***

    we had a wierd issue yesterday. we are using

    new Date(receiptDate).format(‘longDate’)

    for receiptDate on months that have only 30 days, the code was displaying 1 month ahead

    receiptDate = 2/15/2001
    it was showing as
    March 15, 2001

    We verified that all the receiptDates that fell on a month that had 30 days, this issue was occuring.

    Then today when we logged in, everything seems to be ok. All the dates were showing correctly. This is because today is 31 Oct.

    So there seems to be a bug which happens every 30 of the month and if the date that u are trying to display has 30 days inthe month, then the result is off by a month.

    Can you pls look into this?


  304. In chrome it shows “12 Dec 11:04″ and firefox it shows as “12 Dec 06:04″ for .format(“UTC:dd mmm HH:ss”)
    Help me please…

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  306. It’s actually a cool and useful piece of information.
    I’m happy that you just shared this useful information with us.
    Please keep us informed like this. Thank you for sharing.

  307. I wanted to thank you for this excellent read!! I certainly enjoyed every bit of it.
    I have you book marked to look at new things you post…

  308. Hello there! I know this is kinda off topic but
    I’d figured I’d ask. Would you be interested in trading links or
    maybe guest writing a blog post or vice-versa? My site covers a lot of the same topics as yours and I
    think we could greatly benefit from each other. If you might be interested feel free to shoot me an e-mail.

    I look forward to hearing from you! Wonderful blog by the way!

  309. Very good! Very helpfull!
    You best!

  310. Amazing! This blog looks just like my old one! It’s on a
    entirely different topic but it has pretty much the same layout
    and design. Superb choice of colors!

  311. Excellent post. I was checking continuously this blog and I’m impressed!
    Very useful info specially the last part :) I care for such information a
    lot. I was looking for this certain information for a long time.

    Thank you and best of luck.

  312. […] I need to format it in format: “1-Jan-12″. As I found it here it should work like […]

  313. This site was… how do you say it? Relevant!!
    Finally I have found something which helped me. Many thanks!

  314. Hey There. I discovered your weblog the usage of msn. This is
    a really neatly written article. I’ll make sure to bookmark it and return to read more of your useful information.
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