直接上代码：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>js---万年历</title>
<style type="text/css">
*{
margin:0px;
padding:0px;
list-style-type:none;
}
#box{
450px;
height:380px;
border:2px solid #3399ff;
margin:100px auto 0px;
border-radius:5px;
}
#top{
100%;
height:50px;
border-bottom:1px solid #3399ff;
font-size:15px;
}
#year{
margin:15px 10px;
}
#year,#month{
text-align:center;
margin-right:15px;
}
#con{
420px;
height:300px;
margin:0px auto 0px;
}
#con ul.week{
420px;
height:45px;
}
#con ul.week li{
60px;
height:45px;
line-height:45px;
text-align:center;
float:left;
}
#con ul.week li.weekend{color:red}
#con ul.day li{
60px;
height:45px;
border-top:1px solid #ddd;
float:left;
line-height:50px;
text-align:center;
font-size:20px;
}
</style>
</head>
<body>
<div id="box">
<div id="top">
<select name="query-year" id="year">
<option value="">Select year</option>
</select>年
<select name="query-month" id="month">
<option value="">Select month</option>
</select>月
<button style="60px;margin-left:20px;" id="inquriy" onclick="query()">query</button>
</div>
<div id="con">
<ul class="week">
<li class="weekend">日</li>
<li>一</li>
<li>二</i>
<li>三</li>
<li>四</li>
<li>五</li>
<li class="weekend">六</li>
</ul>
<ul class="day">
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
</ul>
</div>
</div>
</body>
<script type="text/javascript">
/*
1 自动生成年份和月份；
2 默认当前年月；
*/
var oYear = document.getElementById('year');
var oMonth = document.getElementById('month');
var oday = document.querySelector('.day');
var oLi = document.querySelectorAll('.day li');
var curDate = new Date();
// 年份
eachFor(1900,2051,function(val){
var option = document.createElement("option");
option.innerHTML = val;
option.value = val;
if(curDate.getFullYear() == val){
option.selected = true;
}
oYear.appendChild(option);
});
// 月份
eachFor(0,11,function(val){
var option = document.createElement("option");
option.innerHTML = parseInt(val) +1;
option.value = val;
if(curDate.getMonth() == val){
option.selected = true;
}
oMonth.appendChild(option);
});
// 对函数的封装应该考虑掺入的参数，大小类型等
function eachFor(start, end, callback){
for(var i = start; i <= end ; i++){
callback(i);
}
}
function query(){
var year = oYear.value ;
var month = oMonth.value ;
// console.log(year +"--"+month);
// oday.innerHTML = '';
if(year && month){
console.log(year +"--"+month);
// 获取月份的第一天
var firstDate = new Date(year,month,1);
// 第一天对应是周几
var dayOfWeek = firstDate.getDay();
// 该月份有多少天
var conutDay = getMonthDays(year,month);
console.log("countDay="+conutDay);
oLi.forEach(function(el,index){
el.innerHTML = '';
})
eachFor(1,conutDay,function(val){
oLi[dayOfWeek + val - 1].innerHTML = val;
});
}else{
alert('请先选择年份和月份');
}
}
// 是否为闰年 整百年份必须被400整除 非整百年份被4整除就都是闰年
function getMonthDays(year,month){
var datas = [];
if(year%400 ==0 || (year%4==0 && year%100!=0)){
// console.log(year + '是闰年');
datas = [31,29,31,30,31,30,31,31,30,31,30.31];
}else{
// console.log(year + '不是闰年');
datas = [31,28,31,30,31,30,31,31,30,31,30.31];
}
console.log(year +"--"+ month +"--"+ datas[month]);
return datas[month];
}
// 初始默认当前时间的年和月进行搜索
query();
</script>
</html>
只是简单实现，还有很多需要完善的地方；