Date Format

Date.prototype.format = function ( format, r, locale ) {
// by Giacomo Trudu
   r = ( typeof r != 'undefined' && r );

   var time = this;

   // Build the Date object
   var date = ( typeof time != 'undefined' ) ? ( time instanceof Date ? time : new Date( time * 1000 ) ) : new Date;

   // Number of seconds since the beginning of this year
   var year_seconds = ( date - new Date( date.getFullYear(), 0, 1 ) ) / 1000;

   // Retrieve the date informations
   var meta = String( date ).match( /^.*?([A-Z]{1,4})([\-+]\d{4}) \(([A-Z]+)\).*$/ );

   date = {

      d : date.getDate(),
      D : date.getDay(),
      m : date.getMonth(),
      y : date.getFullYear(),
      l : ( new Date( date.getFullYear(), 1, 29 ).getMonth() === 1 | 0 ),
      h : date.getHours(),
      M : date.getMinutes(),
      s : date.getSeconds(),
      u : date.getMilliseconds(),
      t : date.getTime(),
      z : date.getTimezoneOffset()
   };

   // Stringa della data formattata
   var timestr = '';

   // Riempie di zeri le cifre alla sinistra di un numero
   var pad = function ( value, len ) {

      return ( '000000000' + String( value ) ).slice( -len );
   };

   	if (!locale) locale = 'it';
	var locale_string = {
		it: {
			D:	[ 'Dom', 'Lun', 'Mar', 'Mer', 'Gio', 'Ven', 'Sab' ],
			l:  [ 'Domenica', 'Lunedì', 'Martedì', 'Mercoledì', 'Giovedì', 'Venerdì', 'Sabato' ],
			S:	[ '', '', '', '' ],
			F:	[ 'Gen', 'Feb', 'Mar', 'Apr', 'Mag', 'Giu', 'Lug', 'Ago', 'Set', 'Ott', 'Nov', 'Dic' ],
			M:	[ 'gennaio', 'febbraio', 'marzo', 'aprile', 'maggio', 'giugno', 'luglio', 'agosto', 'settembre', 'ottobre', 'novembre', 'dicembre' ]
		},
		en: {
			D:	[ 'Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat' ],
			l:	[ 'Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday' ],
			S:	[ 'th', 'st', 'nd', 'rd' ],
			F:	[ 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec' ],
			M:	[ 'January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December' ]
		}
	}

   // Define the format characters
   var fmt_characters = {

      d : function () { return pad( date.d, 2 ); },
      D : function () { return locale_string[locale].D[ date.D ]; },
      j : function () { return date.d; },
      l : function () { return locale_string[locale].l[ date.D ]; },
      N : function () { return date.D + 1; },
      S : function () { return locale_string[locale].S[ date.d % 10 > 3 ? 0 : ( date.d < 10 || date.d > 20 ) * date.d % 10 ]; },
      w : function () { return date.D; },
      z : function () { return Math.ceil( year_seconds / 86400 ); },
      W : function () { return Math.ceil( year_seconds / 604800 ); },
      F : function () { return locale_string[locale].F[ date.m ]; },
      m : function () { return pad( date.m + 1, 2 ); },
      M : function () { return locale_string[locale].M[ date.m ]; },
      n : function () { return date.m + 1; },
      t : function () { return [31, (date.l ? 29 : 28), 31, 30, 31, 30, 31, 31, 30, 31, 30, 31][ date.m ]; },
      L : function () { return date.l; },
      Y : function () { return date.y; },
      y : function () { return String( date.y ).slice( -2 ); },
      a : function () { return ( date.h < 12 ? 'am' : 'pm' ); },
      A : function () { return ( date.h < 12 ? 'AM' : 'PM' ); },
      g : function () { return date.h % 12 || 12; },
      G : function () { return date.h; },
      h : function () { return pad( date.h % 12 || 12, 2 ); },
      H : function () { return pad( date.h, 2 ); },
      i : function () { return pad( date.M, 2 ); },
      s : function () { return pad( date.s, 2 ); },
      u : function () { return date.u * 1000; },
      I : function () { return ( date.m > 2 && date.m < 10 || ( date.m == 2 && date.D - date.d >= 8 - 1 ) ); },
      O : function () { return meta[2]; },
      P : function () { return meta[2].slice( 0, -2 ) + ':' + meta[2].slice( -2 ); },
      T : function () { return meta[3]; },
      Z : function () { return -date.z * 60; },
      c : function () { return ( !r ? formatDate( 'Y-m-d\\TH:i:sP', time, true ) : null ); },
      r : function () { return ( !r ? formatDate( 'D, d M Y H:i:s O', time, true ) : null ); },
      U : function () { return Math.floor( date.t / 1000 ); }
   };

   // Split the format string into tokens
   var tokens = format.match( /(\\.|.)/gi );

   // Make the time string
   for ( var i = 0; i < tokens.length; i++ )
      timestr += ( tokens[i] in fmt_characters ? fmt_characters[ tokens[i] ]() : ( tokens[i].length == 1 ? tokens[i] : tokens[i][1] ) );

   return timestr;
};