js实现天数倒计时
在用js实现倒计时的时候，可以先算出截止日期和今天之间相差的毫秒数，然后进行相应的比例进行day、 month 、hour、minute、second的计算，便可以准确的计算出相差的时间。
倒计时格式为：纯天数倒计时
function CountDown(year, month, day, hours) {let now = new Date();let endDate = new Date(year, month - 1, day, hours);let leftTime = endDate.getTime() - now.getTime();//计算剩余的毫秒数if (leftTime <= 0) {leftTime = 0;}let leftsecond = parseInt(leftTime / 1000);//计算剩余的秒数let countDay = Math.floor(leftsecond / (60 * 60 * 24));return countDay;},//直接调用就好了CountDown(2050, 12, 31, 24)
倒计时格式为：天数+小时+分钟+秒
function CountDown(year, month, day, hours) {let now = new Date();let endDate = new Date(year, month - 1, day, hours);let leftTime = endDate.getTime() - now.getTime();//计算剩余的毫秒数if (leftTime <= 0) {leftTime = 0;}let leftsecond = parseInt(leftTime / 1000);//计算剩余的秒数day = Math.floor(leftsecond / (60 * 60 * 24));let hour = Math.floor((leftsecond - day * 24 * 60 * 60) / 3600);let minute = Math.floor((leftsecond - day * 24 * 60 * 60 - hour * 3600) / 60);let second = Math.floor(leftTime / 1000 % 60, 10);return `${day}天${hour}小时${minute}分钟${second}秒`;}//直接调用即可CountDown(2050, 12, 31, 24)
