为 javascript Date 添加或减去时区差异

Question

向下面的

targetTime

变量添加或减去时区差异的最佳方法是什么。 GMT 时区值来自数据库，格式如下：

1.00

表示伦敦时间，

-8.00

表示太平洋时间，依此类推。

代码如下所示：

date = "September 21, 2011 00:00:00";
targetTime = new Date(date);

Answer 1

您可以使用 Date.getTimezoneOffset 返回与 GMT 的本地偏移量（以分钟为单位）。请注意，它返回的值与您可能期望的符号相反。所以 GMT-5 是 300，GMT+1 是 -60。

var date = "September 21, 2011 00:00:00";
var targetTime = new Date(date);
var timeZoneFromDB = -7.00; //time zone value from database
//get the timezone offset from local time in minutes
var tzDifference = timeZoneFromDB * 60 + targetTime.getTimezoneOffset();
//convert the offset to milliseconds, add to targetTime, and make a new Date
var offsetTime = new Date(targetTime.getTime() + tzDifference * 60 * 1000);

Answer 2

对我有用的简单功能：

adjustForTimezone(date:Date):Date{
    var timeOffsetInMS:number = date.getTimezoneOffset() * 60000;
    date.setTime(date.getTime() + timeOffsetInMS);
    return date
}

Answer 3

如果您需要补偿时区，我会推荐以下代码片段：

var dt = new Date('2018-07-05')
dt.setMinutes(dt.getMinutes() + dt.getTimezoneOffset())
console.log(dt)

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/getTimezoneOffset

getTimezoneOffset() 方法返回在 UTC 时区中计算的日期与在本地时区中计算的相同日期之间的差异（以分钟为单位）。

因此您需要的只是在几分钟内进行补偿

Answer 4

此示例演示如何使用本地日期时间，但将其格式化为 ISO：

const d = new Date();

let dtOffset = new Date(d.setMinutes(d.getMinutes() - d.getTimezoneOffset()));
// Date in EST and ISO format: "2021-11-30T15:33:32.222Z"
console.log(dtOffset.toISOString());

Answer 5

@alexp 答案的打字稿版本

     adjustForTimezone(d:Date, offset:number):Date{
        var date = d.toISOString();
        var targetTime = new Date(date);
        var timeZoneFromDB = offset; //time zone value from database
        //get the timezone offset from local time in minutes
        var tzDifference = timeZoneFromDB * 60 + targetTime.getTimezoneOffset();
        //convert the offset to milliseconds, add to targetTime, and make a new Date
        var offsetTime = new Date(targetTime.getTime() + tzDifference * 60 * 1000);
        return offsetTime;
      } 

Answer 6

adjustForTimezone(date){    
      var targetTime = new Date(date);
      // Manually construct a UTC date string to ensure time components are set consistently
      // This avoids timezone and DST issues entirely
      return new Date(Date.UTC(targetTime.getFullYear(), targetTime.getMonth(), targetTime.getDate()));
}