/*===================================================================
 Author: Matt Kruse
 
 View documentation, examples, and source code at:
     http://www.JavascriptToolbox.com/

 NOTICE: You may use this code for any purpose, commercial or
 private, without any further permission from the author. You may
 remove this notice from your final code if you wish, however it is
 appreciated by the author if at least the web site address is kept.

 This code may NOT be distributed for download from script sites, 
 open source CDs or sites, or any other distribution method. If you
 wish you share this code with others, please direct them to the 
 web site above.
 
 Pleae do not link directly to the .js files on the server above. Copy
 the files to your own server for use with your site or webapp.
 ===================================================================*/
/*
Date functions

These functions are used to parse, format, and manipulate Date objects.
See documentation and examples at http://www.JavascriptToolbox.com/lib/date/

*/
Date.$VERSION = 1.02;

// Utility function to append a 0 to single-digit numbers
Date.LZ = function(x) {return(x<0||x>9?"":"0")+x};
// Full month names. Change this for local month names
Date.monthNames = new Array('January','February','March','April','May','June','July','August','September','October','November','December');
// Month abbreviations. Change this for local month names
Date.monthAbbreviations = new Array('Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec');
// Full day names. Change this for local month names
Date.dayNames = new Array('Sunday','Monday','Tuesday','Wednesday','Thursday','Friday','Saturday');
// Day abbreviations. Change this for local month names
Date.dayAbbreviations = new Array('Sun','Mon','Tue','Wed','Thu','Fri','Sat');
// Used for parsing ambiguous dates like 1/2/2000 - default to preferring 'American' format meaning Jan 2.
// Set to false to prefer 'European' format meaning Feb 1
Date.preferAmericanFormat = false;

// If the getFullYear() method is not defined, create it
if (!Date.prototype.getFullYear) { 
	Date.prototype.getFullYear = function() { var yy=this.getYear(); return (yy<1900?yy+1900:yy); } 
} 

// Parse a string and convert it to a Date object.
// If no format is passed, try a list of common formats.
// If string cannot be parsed, return null.
// Avoids regular expressions to be more portable.
Date.parseString = function(val, format) {
	// If no format is specified, try a few common formats
	if (typeof(format)=="undefined" || format==null || format=="") {
		var generalFormats=new Array('y-M-d','MMM d, y','MMM d,y','y-MMM-d','d-MMM-y','MMM d','MMM-d','d-MMM');
		var monthFirst=new Array('M/d/y','M-d-y','M.d.y','M/d','M-d');
		var dateFirst =new Array('d/M/y','d-M-y','d.M.y','d/M','d-M');
		var checkList=new Array(generalFormats,Date.preferAmericanFormat?monthFirst:dateFirst,Date.preferAmericanFormat?dateFirst:monthFirst);
		for (var i=0; i<checkList.length; i++) {
			var l=checkList[i];
			for (var j=0; j<l.length; j++) {
				var d=Date.parseString(val,l[j]);
				if (d!=null) { 
					return d; 
				}
			}
		}
		return null;
	}

	this.isInteger = function(val) {
		for (var i=0; i < val.length; i++) {
			if ("1234567890".indexOf(val.charAt(i))==-1) { 
				return false; 
			}
		}
		return true;
	};
	this.getInt = function(str,i,minlength,maxlength) {
		for (var x=maxlength; x>=minlength; x--) {
			var token=str.substring(i,i+x);
			if (token.length < minlength) { 
				return null; 
			}
			if (this.isInteger(token)) { 
				return token; 
			}
		}
	return null;
	};
	val=val+"";
	format=format+"";
	var i_val=0;
	var i_format=0;
	var c="";
	var token="";
	var token2="";
	var x,y;
	var year=new Date().getFullYear();
	var month=1;
	var date=1;
	var hh=0;
	var mm=0;
	var ss=0;
	var ampm="";
	while (i_format < format.length) {
		// Get next token from format string
		c=format.charAt(i_format);
		token="";
		while ((format.charAt(i_format)==c) && (i_format < format.length)) {
			token += format.charAt(i_format++);
		}
		// Extract contents of value based on format token
		if (token=="yyyy" || token=="yy" || token=="y") {
			if (token=="yyyy") { 
				x=4;y=4; 
			}
			if (token=="yy") { 
				x=2;y=2; 
			}
			if (token=="y") { 
				x=2;y=4; 
			}
			year=this.getInt(val,i_val,x,y);
			if (year==null) { 
				return null; 
			}
			i_val += year.length;
			if (year.length==2) {
				if (year > 70) { 
					year=1900+(year-0); 
				}
				else { 
					year=2000+(year-0); 
				}
			}
		}
		else if (token=="MMM" || token=="NNN"){
			month=0;
			var names = (token=="MMM"?(Date.monthNames.concat(Date.monthAbbreviations)):Date.monthAbbreviations);
			for (var i=0; i<names.length; i++) {
				var month_name=names[i];
				if (val.substring(i_val,i_val+month_name.length).toLowerCase()==month_name.toLowerCase()) {
					month=(i%12)+1;
					i_val += month_name.length;
					break;
				}
			}
			if ((month < 1)||(month>12)){
				return null;
			}
		}
		else if (token=="EE"||token=="E"){
			var names = (token=="EE"?Date.dayNames:Date.dayAbbreviations);
			for (var i=0; i<names.length; i++) {
				var day_name=names[i];
				if (val.substring(i_val,i_val+day_name.length).toLowerCase()==day_name.toLowerCase()) {
					i_val += day_name.length;
					break;
				}
			}
		}
		else if (token=="MM"||token=="M") {
			month=this.getInt(val,i_val,token.length,2);
			if(month==null||(month<1)||(month>12)){
				return null;
			}
			i_val+=month.length;
		}
		else if (token=="dd"||token=="d") {
			date=this.getInt(val,i_val,token.length,2);
			if(date==null||(date<1)||(date>31)){
				return null;
			}
			i_val+=date.length;
		}
		else if (token=="hh"||token=="h") {
			hh=this.getInt(val,i_val,token.length,2);
			if(hh==null||(hh<1)||(hh>12)){
				return null;
			}
			i_val+=hh.length;
		}
		else if (token=="HH"||token=="H") {
			hh=this.getInt(val,i_val,token.length,2);
			if(hh==null||(hh<0)||(hh>23)){
				return null;
			}
			i_val+=hh.length;
		}
		else if (token=="KK"||token=="K") {
			hh=this.getInt(val,i_val,token.length,2);
			if(hh==null||(hh<0)||(hh>11)){
				return null;
			}
			i_val+=hh.length;
			hh++;
		}
		else if (token=="kk"||token=="k") {
			hh=this.getInt(val,i_val,token.length,2);
			if(hh==null||(hh<1)||(hh>24)){
				return null;
			}
			i_val+=hh.length;
			hh--;
		}
		else if (token=="mm"||token=="m") {
			mm=this.getInt(val,i_val,token.length,2);
			if(mm==null||(mm<0)||(mm>59)){
				return null;
			}
			i_val+=mm.length;
		}
		else if (token=="ss"||token=="s") {
			ss=this.getInt(val,i_val,token.length,2);
			if(ss==null||(ss<0)||(ss>59)){
				return null;
			}
			i_val+=ss.length;
		}
		else if (token=="a") {
			if (val.substring(i_val,i_val+2).toLowerCase()=="am") {
				ampm="AM";
			}
			else if (val.substring(i_val,i_val+2).toLowerCase()=="pm") {
				ampm="PM";
			}
			else {
				return null;
			}
			i_val+=2;
		}
		else {
			if (val.substring(i_val,i_val+token.length)!=token) {
				return null;
			}
			else {
				i_val+=token.length;
			}
		}
	}
	// If there are any trailing characters left in the value, it doesn't match
	if (i_val != val.length) { 
		return null; 
	}
	// Is date valid for month?
	if (month==2) {
		// Check for leap year
		if ( ( (year%4==0)&&(year%100 != 0) ) || (year%400==0) ) { // leap year
			if (date > 29){ 
				return null; 
			}
		}
		else { 
			if (date > 28) { 
				return null; 
			} 
		}
	}
	if ((month==4)||(month==6)||(month==9)||(month==11)) {
		if (date > 30) { 
			return null; 
		}
	}
	// Correct hours value
	if (hh<12 && ampm=="PM") {
		hh=hh-0+12; 
	}
	else if (hh>11 && ampm=="AM") { 
		hh-=12; 
	}
	return new Date(year,month-1,date,hh,mm,ss);
}

// Check if a date string is valid
Date.isValid = function(val,format) {
	return (Date.parseString(val,format) != null);
}

// Check if a date object is before another date object
Date.prototype.isBefore = function(date2) {
	if (date2==null) { 
		return false; 
	}
	return (this.getTime()<date2.getTime());
}

// Check if a date object is after another date object
Date.prototype.isAfter = function(date2) {
	if (date2==null) { 
		return false; 
	}
	return (this.getTime()>date2.getTime());
}

// Check if two date objects have equal dates and times
Date.prototype.equals = function(date2) {
	if (date2==null) { 
		return false; 
	}
	return (this.getTime()==date2.getTime());
}

// Check if two date objects have equal dates, disregarding times
Date.prototype.equalsIgnoreTime = function(date2) {
	if (date2==null) { 
		return false; 
	}
	var d1 = new Date(this.getTime()).clearTime();
	var d2 = new Date(date2.getTime()).clearTime();
	return (d1.getTime()==d2.getTime());
}

// Format a date into a string using a given format string
Date.prototype.format = function(format) {
	format=format+"";
	var result="";
	var i_format=0;
	var c="";
	var token="";
	var y=this.getYear()+"";
	var M=this.getMonth()+1;
	var d=this.getDate();
	var E=this.getDay();
	var H=this.getHours();
	var m=this.getMinutes();
	var s=this.getSeconds();
	var yyyy,yy,MMM,MM,dd,hh,h,mm,ss,ampm,HH,H,KK,K,kk,k;
	// Convert real date parts into formatted versions
	var value=new Object();
	if (y.length < 4) {
		y=""+(+y+1900);
	}
	value["y"]=""+y;
	value["yyyy"]=y;
	value["yy"]=y.substring(2,4);
	value["M"]=M;
	value["MM"]=Date.LZ(M);
	value["MMM"]=Date.monthNames[M-1];
	value["NNN"]=Date.monthAbbreviations[M-1];
	value["d"]=d;
	value["dd"]=Date.LZ(d);
	value["E"]=Date.dayAbbreviations[E];
	value["EE"]=Date.dayNames[E];
	value["H"]=H;
	value["HH"]=Date.LZ(H);
	if (H==0){
		value["h"]=12;
	}
	else if (H>12){
		value["h"]=H-12;
	}
	else {
		value["h"]=H;
	}
	value["hh"]=Date.LZ(value["h"]);
	value["K"]=value["h"]-1;
	value["k"]=value["H"]+1;
	value["KK"]=Date.LZ(value["K"]);
	value["kk"]=Date.LZ(value["k"]);
	if (H > 11) { 
		value["a"]="PM"; 
	}
	else { 
		value["a"]="AM"; 
	}
	value["m"]=m;
	value["mm"]=Date.LZ(m);
	value["s"]=s;
	value["ss"]=Date.LZ(s);
	while (i_format < format.length) {
		c=format.charAt(i_format);
		token="";
		while ((format.charAt(i_format)==c) && (i_format < format.length)) {
			token += format.charAt(i_format++);
		}
		if (typeof(value[token])!="undefined") { 
			result=result + value[token]; 
		}
		else { 
			result=result + token; 
		}
	}
	return result;
}

// Get the full name of the day for a date
Date.prototype.getDayName = function() { 
	return Date.dayNames[this.getDay()];
}

// Get the abbreviation of the day for a date
Date.prototype.getDayAbbreviation = function() { 
	return Date.dayAbbreviations[this.getDay()];
}

// Get the full name of the month for a date
Date.prototype.getMonthName = function() {
	return Date.monthNames[this.getMonth()];
}

// Get the abbreviation of the month for a date
Date.prototype.getMonthAbbreviation = function() { 
	return Date.monthAbbreviations[this.getMonth()];
}

// Clear all time information in a date object
Date.prototype.clearTime = function() {
  this.setHours(0); 
  this.setMinutes(0);
  this.setSeconds(0); 
  this.setMilliseconds(0);
  return this;
}

// Add an amount of time to a date. Negative numbers can be passed to subtract time.
Date.prototype.add = function(interval, number) {
	if (typeof(interval)=="undefined" || interval==null || typeof(number)=="undefined" || number==null) { 
		return this; 
	}
	number = +number;
	if (interval=='y') { // year
		this.setFullYear(this.getFullYear()+number);
	}
	else if (interval=='M') { // Month
		this.setMonth(this.getMonth()+number);
	}
	else if (interval=='d') { // Day
		this.setDate(this.getDate()+number);
	}
	else if (interval=='w') { // Weekday
		var step = (number>0)?1:-1;
		while (number!=0) {
			this.add('d',step);
			while(this.getDay()==0 || this.getDay()==6) { 
				this.add('d',step);
			}
			number -= step;
		}
	}
	else if (interval=='h') { // Hour
		this.setHours(this.getHours() + number);
	}
	else if (interval=='m') { // Minute
		this.setMinutes(this.getMinutes() + number);
	}
	else if (interval=='s') { // Second
		this.setSeconds(this.getSeconds() + number);
	}
	return this;
}