问显示不同系统上的倒计时计时器差异

EN

var countdown = function(){ 
    setInterval(function() {
        var countDownDate = new Date(document.getElementById("end_date").getAttribute("data-date")).getTime(); 
        // data-date ex. = "2017-11-28 21:54:00"; greater than current date (now)
        // Get todays date and time
        var now = new Date().getTime();

        // Find the distance between now an the count down date
        var distance = countDownDate - now;

        // Time calculations for days, hours, minutes and seconds
        var days = Math.floor(distance / (1000 * 60 * 60 * 24));
        var hours = Math.floor((distance % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60));
        var minutes = Math.floor((distance % (1000 * 60 * 60)) / (1000 * 60));
        var seconds = Math.floor((distance % (1000 * 60)) / 1000);

        // Display the result in the element with id="demo"
        if(hours<10){
           hours = "0"+hours;
        }
        if(minutes<10){
           minutes = "0"+minutes;
        }
        if(seconds<10){
           seconds = "0"+seconds;
        }
        var left = hours + ":"+ minutes + ":" + seconds;
        console.log(left);
        document.getElementById("time_left").innerHTML = left;

        // If the count down is finished, write some text
        if (distance < 0) {
            clearInterval(x);
            document.getElementById("time_left").innerHTML = "EXPIRED";
        }
    }, 1000);
}
countdown();