var date1 = new Date(); //实例化现在的时间
var date2 = new Date('2020-12-30 20:36-58');
var dateDis = (date2 - date1) / 1000; //相差的总秒数
var days = parseInt(dateDis / 60 / 60 / 24); //相差总天数
days = days > 10 ? days : "0" + days;
var hours = parseInt(dateDis / 60 / 60 % 24); //相差总小时数
hours = hours > 10 ? hours : "0" + hours;
var minutes = parseInt(dateDis / 60 % 60); //相差总分钟数
minutes = minutes > 10 ? minutes : "0" + minutes;
var seconds = parseInt(dateDis % 60); //相差的总秒数
seconds = seconds > 10 ? seconds : "0" + seconds;
console.log("剩余时间为:" + days + "天" + hours + "时" + minutes + "分钟" + seconds + "秒");