<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>计算今天是今年的第多少天</title>
</head>
<body>
<script>
var date = new Date();
var year = date.getFullYear();
var month = date.getMonth()+1;
var day = date.getDate();
getDate(year,month,day);
//得到天数
function getDate(year,month,day) {
//定义变量天数
var days = day;
var months = [31,28,31,30,31,30,31,31,30,31,30,31];
for(var i = 0 ; i < month - 1 ; i ++){
days += months[i];
}
if( isLeapYear(year) && month>2){
days++;
}
document.write(year+"年已经过去"+days+"天") ;
}
//判断是否为闰年
function isLeapYear(year) {
return year%4 == 0 && year%100 != 0 ||year % 400 == 0;
}
</script>
</body>
</html>