date functions i use

datefunctions.js

Date.prototype.isValid = function() {
 if ( Object.prototype.toString.call(this) !== "[object Date]" )
     return false;
 return !isNaN(this.getTime());
}




////////////
/*
 * 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?|[zLloSZ]|"[^"]*"|'[^']*'/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"](),
			z = date[_ + "Milliseconds"]()*1000,
			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),
        z:    pad(z, 6),
				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",
  IsraelFull:     "d/m/yyyy HH:MM:ss",
  IsraelShort:     "dd/mm/yyyy",
	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",
  mysqlDateTime:  "yyyy-mm-dd HH:MM:ss.z",
  mysqlDateTime2:  "yyyy-mm-dd HH:MM",
	isoTime:        "HH:MM:ss",
	isoDateTime:    "yyyy-mm-dd'T'HH:MM:ss",
  isoDateTime2:    "yyyy-mm-dd HH:MM:ss",
  isoDateTime3:    "yyyy-m-d H:M:s",
	isoUtcDateTime: "UTC:yyyy-mm-dd'T'HH:MM:ss'Z'",
  isoRFC:          "ddd, d mmm yyyy HH:MM:ss o",
  rfc:          "ddd, d mmm yyyy 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);
};
//////////////////End of Date Format lib//////////////////////////

function date_in_GMT(inDate) 
{
    if(!inDate.getTimezoneOffset)return inDate;
    var date = new Date();
    date.setTime(inDate.valueOf() - 60000 * inDate.getTimezoneOffset());
    return date;
}
exports.date_in_GMT=date_in_GMT;



var re_num=/^[-]{0,1}\d+[\.]{0,1}\d*$/;
function make_date(s,dateprefix)
{
 s=s.trim();
 if(s.indexOf('/')!=-1&&s.indexOf(':')!=-1)
 {
  //throw new Error("date parse format not developed  xx:xx xx/xx/xx or xx/xx/xx xx:xx")
  //s.split(':');
 }
 else if(s.length<=5&&s.indexOf(':')!=-1)
 {
  // a.setFullYear(numYear[, numMonth[, numDate]]);
  //a.setHours(numHours[, numMin[, numSec[, numMilli]]]);
  var datepre=dateprefix||(new Date()).toDateString();
  var r=(new Date(datepre+" "+s+":00"));
  //var s=s.split(":");
  //r.setHours(s[0],s[1],s[2]||0)
  return r;
 }
 else if(s.length<=5&&s.indexOf('/')!=-1)
 {
 // throw new Error("date parse format not developed  xx/xx/xx")
 // s.split(':');
 }
 return s;
}

function make_number(s,dateprefix)
{
 if(s.indexOf(':')!=-1||s.indexOf('/')!=-1)
  return make_date(s,dateprefix);
 s=s.trim().replace(/,/g,"").replace('%',"");
 if(re_num.test(s)) return parseFloat(s);
 return s;
}
exports.make_number=make_number;


// actually i don't use the folowing function rather i use
// ver d=new Date()
// d.setDate( d.getDate() +1) // next day - it works in all set date part functions, it simply overflows over and under for negative numbers.
// date manuvers:
// d.setDate( 1)  // first of the month
// d.setDate( 32 );  d.setDate( 1-d.getDate())  // 1st day of the next month
// d.setDate( d.getDate()-1)  // last day of the previous month


Date.prototype.dateAdd=function(timeU,byMany) { 
  
  var millisecond=1;
	var second=millisecond*1000;
	var minute=second*60;
	var hour=minute*60;
	var day=hour*24;
	var year=day*365;

	var newDate;
	var dVal=this.getTime();
	switch(timeU) {
		case "ms": newDate=new Date(dVal+(millisecond*byMany)); break;
		case "s": newDate=new Date(dVal+(second*byMany)); break;
		case "m": newDate=new Date(dVal+(minute*byMany)); break;
		case "h": newDate=new Date(dVal+(hour*byMany)); break;
		case "d": newDate=new Date(dVal+(day*byMany)); break;
		case "y": newDate=new Date(dVal+(year*byMany)); break;
	}
	return newDate;
}