王新阳

<meta charset="utf-8">
<div id="calendar"></div>
<script>
/**
 * edgesun@126.com
 * 20190207
 */
function myCalendar(YEAR,MONTH){
	function isLng(num){return /^(0|([1-9]\d*))$/.test(''+num);}
	var myDate=new Date(), today={year:myDate.getFullYear(), month:myDate.getMonth(), date:myDate.getDate(), ymd:''}; //当前日期
	today.ymd = today.year+ (today.month<9?'0':'')+(today.month+1)+(today.date<10?'0':'')+today.date;
	if(isLng(YEAR) && isLng(MONTH)){
		if(YEAR<2010 || YEAR>2037){alert('不能再翻啦~');return;}
		if(MONTH>11){alert('参数month应该为0到11的整数');return;}
		myDate.setFullYear(YEAR, MONTH, 1);
	}else{
		YEAR = today.year;
		MONTH = today.month;
	}
	
	var PrevNext=[[0,0],[0,0]]; //依次为上一月的年、月，下一月的年、月
	if(MONTH==0){
		PrevNext = [[YEAR-1,11],[YEAR,1]];
	}else if(MONTH==11){
		PrevNext = [[YEAR,10],[YEAR+1,0]];
	}else{
		PrevNext = [[YEAR,MONTH-1],[YEAR,MONTH+1]];
	}
	
	myDate.setDate(1); //当前显示月的第一天
	var weekday=myDate.getDay()?myDate.getDay():7; //当前显示月的第一天是星期几(星期天重置为7，即每周最后一天)
	myDate.setMonth(MONTH+1);
	myDate.setDate(0);
	var totalDays = myDate.getDate(); //当前显示月的总天数
	var html='<table width="100%" border="1" cellpadding="5" cellspacing="0"><thead><tr><th onclick="myCalendar('+PrevNext[0][0]+','+PrevNext[0][1]+')">上个月</th><th colspan="5">'+YEAR+'年'+(MONTH+1)+'月</th><th onClick="myCalendar('+PrevNext[1][0]+','+PrevNext[1][1]+')">下个月</th></tr><tr><th>星期一</th><th>星期二</th><th>星期三</th><th>星期四</th><th>星期五</th><th>星期六</th><th>星期日</th></tr></th><tbody>';
	var n=0, ymd='';
	for(var i=1; i<=42; ++i){
		if(i%7==1) html+='<tr>';
		if(i>=weekday && i<totalDays+weekday){
			++n;
			ymd=''+YEAR+(MONTH<9?'0':'')+(MONTH+1)+(n<10?'0':'')+n;
			html+='<td'+(ymd==today.ymd?' style="background-color:#ddf;"':'')+' data-date="'+ymd+'">'+n+'</td>';
		}else{
			html+='<td></td>';
		}
		if(i%7==0){
			html+='</tr>';
			if(i>=(totalDays+weekday-1))break;
		}
	}
	html+='</tbody></table>';
	document.getElementById('calendar').innerHTML=html;
}

myCalendar();
</script>