JS判断年月
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title></title>
<style type="text/css">
div{
width: 300px;
height: 300px;
border: 1 solid aqua;
}
</style>
</head>
<body>
<script type="text/javascript">
var str = prompt("请输入一个数");
var strs = str.split(" ");
var y = parseInt(strs[0]);
var m = parseInt(strs[1]);
var max =new Date(y,m,0).getDate();
var w = new Date(y +"/"+m +"/"+ "01").getDay();
var html = '<div class="box">'+
'<table>'+
'<tr class ="title"><th colspan ="7">'+y +'年'+m+'月</th></tr>'+
'<tr><td>日</td><td>一</td><td>二</td><td>三</td><td>四</td><td>五</td><td>六</td>';
'<tr>';
for(var d=1;d<=max; ++d){
if(w && d==1){
html+='<td colspan = " ' +w+' "></td>';
}
html +='<td>'+d+'</td>';
if (w==6 && d!=max){
html += '<tr></tr>';
}else if ( d==max ){
html +='</tr>';
}
w =(w +1 >6) ? 0:w +1 ;
}
html += '</table>';
html += '</div>';
document.write(html);
</script>
</body>
</html>