关于倒计时的时区问题

1. 用Ajax获取服务器上的时间，不会被缓存

var now_date = new Date($.ajax({async: false}).getResponseHeader("Date"));
var server_time = now_date.getTime();
/*{$smarty.now}smarty获取服务器上UTC的秒数,但是服务器会缓存，不能用
var now = new Date(parseInt($("#now").val()*1000));//秒数变成毫秒
var nowTime = now.getTime();*/

2. 把end time对应时区的时间转换成秒数

var d = new Date(Date.UTC(2014,7,24,14,0,0));//毫秒
var time = d.getTime();

3. 调用time.js去计算（重点片段代码）

TimerManager.prototype.start = function(dateToCountTo,server_time) { 
    this.totalDuration = dateToCountTo - server_time;
    this.startTime = server_time;
    return this.intervalId = setInterval(this.run, 1000);
};
TimerManager.prototype.run = function() {
    var elapsed, hrs, mins, remaining, secs;
    count = count + 1000;
    //elapsed = new Date().getTime() - this.startTime;
    remaining = this.totalDuration - count;

4. 注意有的时区会有夏令时（把时钟调快了1个小时，需要自己计算一下到达时间）

Date.prototype.stdTimezoneOffset = function() {
        var jan = new Date(this.getFullYear(), 0, 1);
        var jul = new Date(this.getFullYear(), 6, 1);
        return Math.max(jan.getTimezoneOffset(), jul.getTimezoneOffset());
    }
    Date.prototype.dst = function() {
        return this.getTimezoneOffset() < this.stdTimezoneOffset();
    }
    var today = new Date();
    if (today.dst()) { 
        //console.info ("Daylight savings time!");
    }