JavaScript 从时间戳开始计数

Question

我有这个计数器，我想从特定时间戳 (1385132831.818785) 而不是 0 开始。我该怎么做？

startTimer: function(el) {      

         var counter = 0, 
         cDisplay = $(el);
         var format = function(t) {

             var minutes = Math.floor(t/600),
                 seconds = Math.floor( (t/10) % 60);
             minutes = (minutes === 0) ? "" : (minutes === 1)? minutes.toString()     + ' min ' : minutes.toString() + ' mins ';
             seconds = (seconds === 0) ? "" : seconds.toString() + ' secs';
             cDisplay.html(minutes + seconds);
         };
        setInterval(function() {
           counter++;
           format(counter);
        },100);

    }

Answer 1

尝试

var el = '.timer';
var start = 1385132831,
    cDisplay = $(el);
var format = function (t) {
    var hours = Math.floor(t / 3600),
        minutes = Math.floor(t / 60 % 60),
        seconds = Math.floor(t % 60),
        arr = [];
    if (hours > 0) {
        arr.push(hours == 1 ? '1 hr' : hours + 'hrs');
    }
    if (minutes > 0 || hours > 0) {
        arr.push(minutes > 1 ? minutes + ' mins' : minutes + ' min');
    }
    if (seconds > 0 || minutes > 0 || hours > 0) {
        arr.push(seconds > 1 ? seconds + ' secs' : seconds + ' sec');
    }
    cDisplay.html(arr.join(' '));
};
setInterval(function () {
    format(new Date().getTime() / 1000 - start);
}, 1000);

演示:Fiddle