dateformat

A node.js package for Steven Levithan's excellent dateFormat() function.

Modifications

• Removed the Date.prototype.format method. Sorry folks, but extending native prototypes is for suckers.
• Added a module.exports = dateFormat; statement at the bottom
• Added the placeholder N to get the ISO 8601 numeric representation of the day of the week

Installation

$ npm install dateformat
$ dateformat --help

Usage

As taken from Steven's post, modified to match the Modifications listed above:

import dateFormat, { masks } from "dateformat";
const now = new Date();

// Basic usage
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
dateFormat(now, "isoDateTime");
// 2007-06-09T17:46:21

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

// 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
dateFormat(now);
// Sat Jun 09 2007 17:46:21

// And if you don't include the date argument,
// the current date and time is used
dateFormat();
// 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
dateFormat("longTime");
// 5:46:22 PM EST

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

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

// You can also get the ISO 8601 week of the year:
dateFormat(now, "W");
// 42

// and also get the ISO 8601 numeric representation of the day of the week:
dateFormat(now, "N");
// 6

Mask options

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.
DDD	"Ysd", "Tdy" or "Tmw" if date lies within these three days. Else fall back to ddd.
dddd	Day of the week as its full name.
DDDD	"Yesterday", "Today" or "Tomorrow" if date lies within these three days. Else fall back to dddd.
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.
MM	Minutes; leading zero for single-digit minutes.
N	ISO 8601 numeric representation of the day of the week.
o	GMT/UTC timezone offset, e.g. -0500 or +0230.
p	GMT/UTC timezone offset, e.g. -05:00 or +02:30.
s	Seconds; no leading zero for single-digit seconds.
ss	Seconds; leading zero for single-digit seconds.
S	The date's ordinal suffix (st, nd, rd, or th). Works well with d.
l	Milliseconds; gives 3 digits.
L	Milliseconds; gives 2 digits.
t	Lowercase, single-character time marker string: a or p.
tt	Lowercase, two-character time marker string: am or pm.
T	Uppercase, single-character time marker string: A or P.
TT	Uppercase, two-character time marker string: AM or PM.
W	ISO 8601 week number of the year, e.g. 4, 42
WW	ISO 8601 week number of the year, leading zero for single-digit, e.g. 04, 42
Z	US timezone abbreviation, e.g. EST or MDT. For non-US timezones, the GMT/UTC offset is returned, e.g. GMT-0500
'...', "..."	Literal character sequence. Surrounding quotes are removed.
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.

Named Formats

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
paddedShortDate	mm/dd/yyyy	06/09/2007
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:sso	2007-06-09T17:46:21+0700
isoUtcDateTime	UTC:yyyy-mm-dd'T'HH:MM:ss'Z'	2007-06-09T22:46:21Z

Localization

Day names, month names and the AM/PM indicators can be localized by passing an object with the necessary strings. For example:

import { i18n } from "dateformat";

i18n.dayNames = [
  "Sun",
  "Mon",
  "Tue",
  "Wed",
  "Thu",
  "Fri",
  "Sat",
  "Sunday",
  "Monday",
  "Tuesday",
  "Wednesday",
  "Thursday",
  "Friday",
  "Saturday",
];

i18n.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",
];

i18n.timeNames = ["a", "p", "am", "pm", "A", "P", "AM", "PM"];

Notice that only one language is supported at a time and all strings must be present in the new value.

Breaking change in 2.1.0

• 2.1.0 was published with a breaking change, for those using localized strings.
• 2.2.0 has been published without the change, to keep packages refering to ^2.0.0 to continue working. This is now branch v2_2.
• 3.0.* contains the localized AM/PM change.

License

(c) 2007-2009 Steven Levithan stevenlevithan.com, MIT license.