jQuery(document).ready(function($){
	
	//カレンダー初期
	var data = new Date();
	var year = data.getYear();
	year = (year < 2000) ? year + 1900 : year;
	var month = data.getMonth() + 1;
	var today = data.getDate();
	data.setDate(1);
	var startday = data.getDay();
	var weeks = new Array('Sun','Mon','Tue','Wed','Thu','Fri','Sat');
	var monthdays = new Array(31,28,31,30,31,30,31,31,30,31,30,31);
	var datemax = monthdays[month-1]; 
	if (month == 2 && ((year%4 == 0 && year%100 != 0) || year%400 == 0)) {datemax = 29;}
		
	//初期カレンダー作成
	$('#calendar').html('<p class="title"><span id="backmonth">&lt;&lt;前月</span><span class="time">'+year+'年'+month+'月</span><span id="nextmonth">次月&gt;&gt;</span></p><table border="0" cellpadding="0" cellspacing="0" ></table>');
	
	//週
	var week = '';
    week += '<tr><th class="sun">'+weeks[0]+'</th>';
    for (var i =1; i < 6; i++){
        week += '<th>'+weeks[i]+'</th>';
    }
    week += '<th class="sut">'+weeks[6]+'</th></tr>';
    $('#calendar table').append(week);
	
	//日付
	var col = 0;
	var days = '';
	var num = '';
	if(startday > 0) {
		days += '<tr>';
		for (; col < startday; col++) {
			days += '<td>&nbsp;</td>';
		}
	}
	for (i = 1; i <= datemax; i++) {
		if (i == today){
			num = '<strong>'+i+'</strong>';
		} else {
			num = i;
		}
		
		if (col == 0){
			days += '<tr><td class="sun">'+num+'</td>';
			col++;
		}else if (col == 6){
			days += '<td class="sut">'+num+'</td></tr>';
			col = 0;
		}else{
			days += '<td>'+num+'</td>';
			col++;
		}
	}
	if (col != 0) {
		for (; col < 7; col++) {
			days += '<td>&nbsp;</td>';
		};
		days += '</tr>';   
	}
	 $('#calendar table').append(days);
	 
	 
	 //カレンダー作成
	  function calender (year,month,weeks,startday,datemax,today) {
		var div = "";
		
		//週
		div += '<tr><th class="sun">'+weeks[0]+'</th>';
		for (var i =1; i < 6; i++){
			div += '<th>'+weeks[i]+'</th>';
		}
		div += '<th class="sut">'+weeks[6]+'</th></tr>';
		$("#calendar table").html(div);
		
		//日付
		var col = 0;
		var num = '';
		var div2 = "";
		var tomonth = data.getMonth() + 1;
		var toyear = data.getFullYear();
		if(startday > 0) {
			div2 += '<tr>';
			for (; col < startday; col++) {
				div2 += '<td>&nbsp;</td>';
			}
		}
		for (i = 1; i <= datemax; i++) {
			if (i == today && year == toyear && tomonth == month){
				num = '<strong>'+i+'</strong>';
			} else {
				num = i;
			};
			
			if (col == 0){
				div2 += '<tr><td class="sun">'+num+'</td>';
				col++;
			}else if (col == 6){
				div2 += '<td class="sut">'+num+'</td></tr>';
				col = 0;
			}else{
				div2 += '<td>'+num+'</td>';
				col++;
			}
		}
		if (col != 0) {
			for (; col < 7; col++) {
				div2 += '<td>&nbsp;</td>';
			};
			div2 += '</tr>';   
		}
		
		$("#calendar .title .time").html(year+'年'+month+'月');
		$("#calendar table").html(div + div2);
	};
	
	 
	$("#backmonth").click(function () {
		if(month == 1){month = 12; year -= 1;}else{month -= 1;}
		var backmonth = new Date(year,month-1,1);
		startday = backmonth.getDay();
		datemax = monthdays[month-1];
		if(month == 2 && ((year%4 == 0 && year%100 != 0) || year%400 == 0)) {datemax = 29;}
		calender (year,month,weeks,startday,datemax,today);
	});

	$("#nextmonth").click(function () {
		if(month == 12){month = 1; year += 1;}else{month += 1;}
		var nextmonth = new Date(year,month-1,1);
		startday = nextmonth.getDay();
		datemax = monthdays[month-1];
		if(month == 2 && ((year%4 == 0 && year%100 != 0) || year%400 == 0)) {datemax = 29;}
		calender (year,month,weeks,startday,datemax,today);
	});
	
});