This is date formatter with caching system for decoded format string for Node.JS

var dates = require('dates');

// Format a date without cache using a standard format.
console.log(dates.format(dates.standardFormat.ISO8601), new Date());

// Format a date with cache and custom format.
var formatter = dates.createFormatter("The date is: ddd dd MMMM yyyy - hh:mm:ss.sss $a");
console.log(formatter.format(new Date));

// Format a date with a different local (here french).
formatter = dates.createFormatter("La date est : www dd MMMM yyyy - HH:mm:ss.sss", 'fr');
console.log(formatter.format(new Date));

• format( {string} formatString [, {Date} date ] [, {string} local ]) -> {string} - format a date.
• createFormatter( {string} formatString [, {string} local ]) -> {DateFormatter} - return a date formatter.
• DateFormatter::format( {Date} date ) -> {string} - format a date.

• dd: The day in the month with 0 before if necessary.

• ww: The number of the day in the week (from 1 to 7).

• www: The day in the week in 3 letters (Sun for Sunday).

• wwww: The day in the week in full letter.

• MM: The month with 0 before if necessary.

• MMM: The month in 3 letters (Jan for January).

• MMMM: The month in full letters.

• yy: The year on 2 digits (14 for 2014 or 1914).

• yyyy: The full year.

• hh: The hour in official 12 hours system (12 for midnight an midday).

• HH: The hour in 24 hours system (0 for midnight).

• $a: The day period indicator in lower case (am or pm).

• $A: The day period indicator in upper case (AM or PM).

• mm: The minutes.

• ss: The seconds.

• sss: The milliseconds.

• ISO8601: "yyyy-MM-ddThh:mm:ss.sssZ"
• DATETIME: "yyyy-MM-dd hh:mm:ss"

When you create a formatter the format string is read to extract the format process and compile it in an array.

The compiler search two type of element:

• date symbols: referenced previously
• user string: string not recognized

The user string is store as it in the array and the date symbols are converted in formatting functions what referenced in dictionary.js.

When you call the method format, the array is read to concatenate the user string and the result of formatting functions.

Your original format string is never read again as long you keep the same formatter object.

You can change the local of the name of the days and mouths with the local parameter. The available locals are stored at ./libs/i18n/.