倒计时

有一个商品列表，每个商品需要有个倒计时。数据如下：
var data = [{ID:1,Time:'2019-06-30 10:30:00'},{ID:2,Time:'2019-04-3 18:30:00'},{ID:3,Time:'2018-05-30 1:30:00'}];用Js或JQ写出实现代码
注:Time是指倒计时结束时间

let data = [{ID:1,Time:'2019-06-30 10:30:00'},{ID:2,Time:'2019-04-3 18:30:00'},{ID:3,Time:'2018-05-30 1:30:00'}];
let now = Date.now();
function timer() {
    setTimeout(() => {
        data.forEach(item =>{
            if (!item.countdown){
                item.countdown = new Date(item.Time).getTime()-now;
            }if (item.countdown<0) {
                item.countdown=0;
            }else {
                item.countdown=item.countdown-1000
            }

        })
        if (data.some(item=>item.countdown!==0)){
            timer()
        }
    },1000)
}
timer()