5、用JS写一个当年还剩多少时间的倒计时程序

<script>
var fullyear = (new Date()).getFullYear();
var nextyear = fullyear + 1;
//本年的最后一毫秒：
var lastday = new Date(new Date(nextyear,0,1) - 1);

var now = new Date();
var diff = lastday - now;  //毫秒数
var tian = Math.floor(diff / (1000 * 60 * 60 * 24));

var shi = Math.floor(diff % (1000 * 60 * 60 * 24) / (1000 * 60 * 60));
var fen = Math.floor(diff % (1000 * 60 * 60 * 24) % (1000 * 60 * 60) / (1000 * 60));
var miao = Math.floor(diff % (1000 * 60 * 60 * 24) % (1000 * 60 * 60) % (1000 * 60) / 1000);
console.log(tian)
console.log(shi)
console.log(fen)
console.log(miao)
</script>