Javascript Date常用処理関数

//             
Date.diffDayHourString = function(date1,date2){
	var date3;
	if(typeof date1 == "object"){
		date3=date2.getTime()-date1.getTime();  //       
	}
	else{
		date3=date2-date1;  //       
	}
	var days=Math.floor(date3/(24*3600*1000));
	var leave1=date3%(24*3600*1000);    //           
	var hours=Math.floor(leave1/(3600*1000));
	return days+"D "+hours+"H";
}

//            
Date.diffHourInt = function(date1,date2){
	var date3;
	if(typeof date1 == "object"){
		date3=date2.getTime()-date1.getTime();  //       
	}
	else{
		date3=date2-date1;  //       
	}
	var days=Math.floor(date3/(24*3600*1000));
	var leave1=date3%(24*3600*1000);    //           
	var hours=Math.floor(leave1/(3600*1000));
	return days*24+hours;
}


Date.getTime = function(dateStr/*yyyy-MM-dd HH:mm:ss*/){
	var d = new Date(dateStr);
	return d.getTime();
}

Date.MONTH_DAYS = [31,0,31,30,31,30,31,31,30,31,30,31];
Date.ENG_MONTH_MAP = {'Jan':1, 'Feb':2, 'Mar':3, 'Apr':4, 'May':5, 'Jun':6, 'Jul':7, 'Aug':8, 'Sep':9, 'Oct':10, 'Nov':11, 'Dec':12};
Date.MONTH_ENG_MAP = ['Jan','Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'];

//        
Date.getMonthDays = function(year,month){
	year-=0;month-=0;
	if(month==1){
		if (0==year%4&&((year%100!=0)||(year%400==0)))return 29
		else return 28;
	}
	else return Date.MONTH_DAYS[month];
}

/**
 *      ，              
 *                
 *                
 *      =          +       
 *                           
 * */
Date.getStartEndDateOfWeek = function(year,numOfWeek,outStr){
	year-=0;numOfWeek-=1;
	var b = new Date(year,0,1),bDayOfWeek = b.getDay()||7,
		startDate = new Date(),endDate = new Date(),
		extraDays = (7-bDayOfWeek+1),fullDays;
	if(extraDays!=7) {
		numOfWeek -= 1; 
		fullDays = numOfWeek*7+extraDays;
	}
	else{
		fullDays = numOfWeek*7;
	}

	startDate.setTime(new Date(year,0,1).getTime() + (fullDays <= 0 ? 0 : fullDays*24*60*60*1000));
	endDate.setTime(startDate.getTime() + (numOfWeek < 0 && extraDays != 7 ? extraDays-1 : 6 )*24*60*60*1000);
	if(endDate.getFullYear() > year){
		endDate = new Date(year,11,31);
	}
	//console.log(startDate.toString(),endDate.toString());
	if(outStr){
		return (startDate.getMonth()+1)+"."+startDate.getDate()+"~"+(endDate.getMonth()+1)+"."+endDate.getDate();
	}
	else{
		return [startDate,endDate];
	}
	
}

//     
Date.prototype.format = function (formatStr) {   
	var date = this;   
	/*   
	  ：  0     
	  ：value-        , length-      
	  ：          
	*/  
	var zeroize = function (value, length) {   
		if (!length) {   
			length = 2;   
		}   
		value = new String(value);   
		for (var i = 0, zeros = ''; i < (length - value.length); i++) {   
			zeros += '0';   
		}   
		return zeros + value;   
	};   
	return formatStr.replace(/"[^"]*"|'[^']*'|\b(?:d{1,4}|M{1,4}|yy(?:yy)?|([hHmstT])\1?|[lLZ])\b/g, function($0) {   
		switch ($0) {   
			case 'd': return date.getDate();   
			case 'dd': return zeroize(date.getDate());   
			case 'ddd': return ['Sun', 'Mon', 'Tue', 'Wed', 'Thr', 'Fri', 'Sat'][date.getDay()];   
			case 'dddd': return ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'][date.getDay()];   
			case 'M': return date.getMonth() + 1;   
			case 'MM': return zeroize(date.getMonth() + 1);   
			case 'MMM': return ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'][date.getMonth()];   
			case 'MMMM': return ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'][date.getMonth()];   
			case 'yy': return new String(date.getFullYear()).substr(2);   
			case 'yyyy': return date.getFullYear();   
			case 'h': return date.getHours() % 12 || 12;   
			case 'hh': return zeroize(date.getHours() % 12 || 12);   
			case 'H': return date.getHours();   
			case 'HH': return zeroize(date.getHours());   
			case 'm': return date.getMinutes();   
			case 'mm': return zeroize(date.getMinutes());   
			case 's': return date.getSeconds();   
			case 'ss': return zeroize(date.getSeconds());   
			case 'l': return date.getMilliseconds();   
			case 'll': return zeroize(date.getMilliseconds());   
			case 'tt': return date.getHours() < 12 ? 'am' : 'pm';   
			case 'TT': return date.getHours() < 12 ? 'AM' : 'PM';   
		}   
	});   
}

//            
Date.prototype.getMonthWeek = function () {    
    var date = this, w = date.getDay(), d = date.getDate();    
    return Math.ceil((d + 6 - w) / 7);    
};    

//            
Date.prototype.getYearWeek = function () {       
    var date1 = this, date2 = new Date(date1.getFullYear(), 0, 1),    
        d = Math.round((date1.valueOf() - date2.valueOf()) / 86400000);    
    return Math.ceil((d + (((date2.getDay()||7) + 1) - 1)) / 7);    
};