根据开始时间和结束时间实现倒计时效果


    getDate() {       var time_now_server, time_now_client, time_end, time_server_client;       time_end = new Date("2020 07 22 18:50:50");//结束的时间       time_end = time_end.getTime();       time_now_server = new Date("2020 07 21 16:35:35");//开始的时间       time_now_server = time_now_server.getTime();       time_now_client = new Date();       time_now_client = time_now_client.getTime();       time_server_client = time_now_server - time_now_client;       var timeFunction = () => {         var time_now, time_distance, str_time;         var time_now = new Date();         time_now = time_now.getTime() + time_server_client;         time_distance = time_end - time_now;         if (time_distance > 0) {           this.day = Math.floor(time_distance / 86400000)           time_distance -= this.day * 86400000;           this.h = Math.floor(time_distance / 3600000)           time_distance -= this.h * 3600000;           this.m = Math.floor(time_distance / 60000)           time_distance -= this.m * 60000;           this.s = Math.floor(time_distance / 1000)           if (this.h < 10)             this.h = "0" + this.h;           if (this.m < 10)             this.m = "0" + this.m;           if (this.s < 10)             this.s = "0" + this.s;         } else {           clearInterval(go);         }       }       timeFunction();       let go = setInterval(function () {         timeFunction();       }, 1000);     },