如何防止javascript将我的日期转换为GMT？

Question

I have a timestamp given by

timestamp = 2015-02-22T10:00:00.000Z

Why is it converted to GMT when I do this

var dt = new Date(timestamp);
console.log('dt = ' + dt); // prints Sun Feb 22 2015 05:00:00 GMT-0500 (EST)

I don't want it to convert my date to GMT. How do I prevent javascript from converting my dates?

Answer 1

When you try to execute dt = ' + dt , Javascript tries to convert the dt object to a string so it can be added to another string. It does that by calling the dt.toString() method and the format you are seeing is the default string conversion for a date object.

FYI, this default format that looks like this:

Fri Mar 06 2015 19:24:42 GMT-0800 (Pacific Standard Time)

is NOT GMT time. The time value shown is local time. It is showing you that local time shown is -0800 hours from GMT, but the time itself is expressed in local time.

It's not uncommon to want to just truncate off the last part of this and display:

Fri Mar 06 2015 19:24:42

That can be done like this:

console.log('dt = ' + dt.toString().replace(/\sGMT.*$/, ""));

Working demo: http://jsfiddle.net/jfriend00/hg5m0r1r/

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If you want something different to show, then you should construct the string representation you want yourself rather than letting the system automatically call .toString() . You can look at the Date object methods available and decide what you want to display. A Date object internally is a number of ms since the epoch time so any string representation is a conversion of some kind. You have to tell it what conversion you want.

You can see a list of the many date methods here .