Javascript日期：处理夏令时的最佳方法是什么？

时间：2010-11-05 21:00:49

标签： javascript date

在之前的一个问题中，我写了一篇关于javascript日期函数的文章，它在11/07/101神秘地停止了。感谢stackoverflow用户，我被告知我的问题是夏令时。 Javascript date, is this my error or did I find a bug?

所以我对此的最后一个问题是Javascript中推荐的处理夏令时的方法是什么？

http://code.google.com/p/datejs/是解决此问题的最佳方法吗？

3 个答案:

答案 0 :(得分：19)

最好的办法是不要处理夏令时。使用UTC方法，您不必担心跨越DST边界或任何其他时区不连续（区域设置时区规则可能因为更多原因而不仅仅是DST而发生变化）。

var timestamp= Date.UTC(2010, 10-1, 31, 0, 0, 0); // zero-based month: 9->october
var nextday= new Date(timestamp+86400000); // add one day
var ymd= [
    nextday.getUTCFullYear(),
    nextday.getUTCMonth()+1, // zero-based month
    nextday.getUTCDate()
].join('-');
alert(ymd); // 2010-11-1

如果使用new Date(2010, ...)和getDate()等完成上述操作，则会返回2010-10-31，由于DST更改（在我所在的地区，无论如何），添加失败的那一天。

遗憾的是Date中'默认'最明显的方法是关于本地时间的，特别是因为JavaScript在“本地时间”实际上为脚本提供了非常少的上下文。 UTC是一个更稳定的主张。

答案 1 :(得分：2)

使用Date.setHours(hour,min,sec,millisec)将小时默认设置为中午： Date.setHours(11);（view reference）

一天中午24小时后保证是第二天，但在夏令时，它将减少一个小时（这根本不会改变你的剧本中的结果）。

答案 2 :(得分：0)

我遇到的情况是我需要在当地时区的日期，我通过时间戳做了很多添加和减去日期，一段时间之后DST给了我一些问题，我做了一个函数来增加一天的时间时间戳并检查时区是否改变了DST的原因
Heres是我的暂存测试：

function timeToHuman(stamp) {
    var monthNames = ["January", "February", "March", "April", "May", "June",
            "July", "August", "September", "October", "November", "December"],
        date = new Date(stamp*1000),
        month = monthNames[date.getMonth()],
        day = date.getDate(),
        year = date.getFullYear(),
        hour = date.getHours(),
        min = date.getMinutes(),
        amp;
    if(hour>11){
        hour -= 12;
        amp = "PM";
    }
    else
        amp="AM";
    hour = hour==0?12:hour;
    min = min<10?"0"+min:min;
    return month + " " + day + ", " + year + " @ " +  hour + ":" + min + " " + amp +// Month/Day /Year
        " || "+year+"/"+(date.getMonth()+1)+"/"+day+ " @ " +  date.getHours() + ":" + min;// Year/Month/Day
}
function addDays(stamp,days){//stamp = new Date().getTime()/1000
    var sec=days*86400,
        B4=new Date(stamp*1000).getTimezoneOffset(),
        A=new Date((stamp+sec)*1000).getTimezoneOffset();
    if(B4!=A){// DST correction
        A=(A-B4)*60;
        console.log('DST adjust by:',A,'seconds');
        sec+=A;
    }
    return stamp+sec;
}
var sample=[
         Math.floor(new Date('Sun Mar 10 2018 11:38:59 GMT-0500 (EDT)').getTime()/1000),// day before DST change
         Math.floor(new Date('Sun Mar 11 2018 11:38:59 GMT-0400 (EDT)').getTime()/1000),// day after DST change
         Math.floor(new Date('Sun Nov 3 2018 11:38:59 GMT-0400 (EDT)').getTime()/1000),// day before DST change
         Math.floor(new Date('Sun Nov 4 2018 11:38:59 GMT-0500 (EDT)').getTime()/1000)// day after DST change
      ]
    date=[];
for(i in sample){
    i=parseInt(i,10);
  date.push('Without DST Detection, Part '+(i+1));
  date.push('\t'+timeToHuman(sample[i]+2*86400));
  date.push('\t'+timeToHuman(sample[i]+1*86400));
  date.push('\t'+timeToHuman(sample[i]));
  date.push('\t'+timeToHuman(sample[i]+-1*86400));
  date.push('\t'+timeToHuman(sample[i]+-2*86400));
  date.push('\t'+timeToHuman(sample[i]+-3*86400));
  date.push('With DST Detection, Part '+(i+1));
  date.push('\t'+timeToHuman(addDays(sample[i],2)));
  date.push('\t'+timeToHuman(addDays(sample[i],1)));
  date.push('\t'+timeToHuman(sample[i]));
  date.push('\t'+timeToHuman(addDays(sample[i],-1)));
  date.push('\t'+timeToHuman(addDays(sample[i],-2)));
  date.push('\t'+timeToHuman(addDays(sample[i],-3)));
}
date.join('\n');

/*
Without DST Detection, Part 1
    March 12, 2018 @ 12:38 PM || 2018/3/12 @ 12:38
    March 11, 2018 @ 12:38 PM || 2018/3/11 @ 12:38
    March 10, 2018 @ 11:38 AM || 2018/3/10 @ 11:38
    March 9, 2018 @ 11:38 AM || 2018/3/9 @ 11:38
    March 8, 2018 @ 11:38 AM || 2018/3/8 @ 11:38
    March 7, 2018 @ 11:38 AM || 2018/3/7 @ 11:38
With DST Detection, Part 1
    March 12, 2018 @ 11:38 AM || 2018/3/12 @ 11:38
    March 11, 2018 @ 11:38 AM || 2018/3/11 @ 11:38
    March 10, 2018 @ 11:38 AM || 2018/3/10 @ 11:38
    March 9, 2018 @ 11:38 AM || 2018/3/9 @ 11:38
    March 8, 2018 @ 11:38 AM || 2018/3/8 @ 11:38
    March 7, 2018 @ 11:38 AM || 2018/3/7 @ 11:38
Without DST Detection, Part 2
    March 13, 2018 @ 11:38 AM || 2018/3/13 @ 11:38
    March 12, 2018 @ 11:38 AM || 2018/3/12 @ 11:38
    March 11, 2018 @ 11:38 AM || 2018/3/11 @ 11:38
    March 10, 2018 @ 10:38 AM || 2018/3/10 @ 10:38
    March 9, 2018 @ 10:38 AM || 2018/3/9 @ 10:38
    March 8, 2018 @ 10:38 AM || 2018/3/8 @ 10:38
With DST Detection, Part 2
    March 13, 2018 @ 11:38 AM || 2018/3/13 @ 11:38
    March 12, 2018 @ 11:38 AM || 2018/3/12 @ 11:38
    March 11, 2018 @ 11:38 AM || 2018/3/11 @ 11:38
    March 10, 2018 @ 11:38 AM || 2018/3/10 @ 11:38
    March 9, 2018 @ 11:38 AM || 2018/3/9 @ 11:38
    March 8, 2018 @ 11:38 AM || 2018/3/8 @ 11:38
Without DST Detection, Part 3
    November 5, 2018 @ 10:38 AM || 2018/11/5 @ 10:38
    November 4, 2018 @ 10:38 AM || 2018/11/4 @ 10:38
    November 3, 2018 @ 11:38 AM || 2018/11/3 @ 11:38
    November 2, 2018 @ 11:38 AM || 2018/11/2 @ 11:38
    November 1, 2018 @ 11:38 AM || 2018/11/1 @ 11:38
    October 31, 2018 @ 11:38 AM || 2018/10/31 @ 11:38
With DST Detection, Part 3
    November 5, 2018 @ 11:38 AM || 2018/11/5 @ 11:38
    November 4, 2018 @ 11:38 AM || 2018/11/4 @ 11:38
    November 3, 2018 @ 11:38 AM || 2018/11/3 @ 11:38
    November 2, 2018 @ 11:38 AM || 2018/11/2 @ 11:38
    November 1, 2018 @ 11:38 AM || 2018/11/1 @ 11:38
    October 31, 2018 @ 11:38 AM || 2018/10/31 @ 11:38
Without DST Detection, Part 4
    November 6, 2018 @ 11:38 AM || 2018/11/6 @ 11:38
    November 5, 2018 @ 11:38 AM || 2018/11/5 @ 11:38
    November 4, 2018 @ 11:38 AM || 2018/11/4 @ 11:38
    November 3, 2018 @ 12:38 PM || 2018/11/3 @ 12:38
    November 2, 2018 @ 12:38 PM || 2018/11/2 @ 12:38
    November 1, 2018 @ 12:38 PM || 2018/11/1 @ 12:38
With DST Detection, Part 4
    November 6, 2018 @ 11:38 AM || 2018/11/6 @ 11:38
    November 5, 2018 @ 11:38 AM || 2018/11/5 @ 11:38
    November 4, 2018 @ 11:38 AM || 2018/11/4 @ 11:38
    November 3, 2018 @ 11:38 AM || 2018/11/3 @ 11:38
    November 2, 2018 @ 11:38 AM || 2018/11/2 @ 11:38
    November 1, 2018 @ 11:38 AM || 2018/11/1 @ 11:38
*/
相关问题
最新问题