I believe d.toDateString() will output the format you're looking for.

var d = new Date();
d.setTime(1432851021000);
d.toDateString(); // outputs to "Thu May 28 2015"
d.toGMTString(); //outputs to "Thu, 28 May 2015 22:10:21 GMT"

Or even d.toLocaleString() "5/28/2015, 6:10:21 PM"

There are lots of methods available to Date()

I had the same issue. I get a date as a String, for example: '2016-08-25T00:00:00', but I need to have the Date object with correct time. To convert String into object, I use getTimezoneOffset:

var date = new Date('2016-08-25T00:00:00')
var userTimezoneOffset = date.getTimezoneOffset() * 60000;
new Date(date.getTime() + userTimezoneOffset);

getTimezoneOffset() will return ether negative or positive value. This must be subtracted to work in every location in world.

A Date object's underlying value is actually in UTC. To prove this, notice that if you type new Date(0) you'll see something like: Wed Dec 31 1969 16:00:00 GMT-0800 (PST). 0 is treated as 0 in GMT, but .toString() method shows the local time.

Big note, UTC stands for Universal time code. The current time right now in 2 different places is the same UTC, but the output can be formatted differently.

What we need here is some formatting

var _date = new Date(1270544790922); 
// outputs > "Tue Apr 06 2010 02:06:30 GMT-0700 (PDT)", for me
_date.toLocaleString('fi-FI', { timeZone: 'Europe/Helsinki' });
// outputs > "6.4.2010 klo 12.06.30"
_date.toLocaleString('en-US', { timeZone: 'Europe/Helsinki' });
// outputs > "4/6/2010, 12:06:30 PM"

This works but.... you can't really use any of the other date methods for your purposes since they describe the user's timezone. What you want is a date object that's related to the Helsinki timezone. Your options at this point are to use some 3rd party library (I recommend this), or hack-up the date object so you can use most of it's methods.

Option 1 - a 3rd party like moment-timezone

moment(1270544790922).tz('Europe/Helsinki').format('YYYY-MM-DD HH:mm:ss')
// outputs > 2010-04-06 12:06:30
moment(1270544790922).tz('Europe/Helsinki').hour()
// outputs > 12

This looks a lot more elegant than what we're about to do next.

Option 2 - Hack up the date object

var currentHelsinkiHoursOffset = 2; // sometimes it is 3
var date = new Date(1270544790922);
var helsenkiOffset = currentHelsinkiHoursOffset*60*60000;
var userOffset = _date.getTimezoneOffset()*60000; // [min*60000 = ms]
var helsenkiTime = new Date(date.getTime()+ helsenkiOffset + userOffset);
// Outputs > Tue Apr 06 2010 12:06:30 GMT-0700 (PDT)

It still thinks it's GMT-0700 (PDT), but if you don't stare too hard you may be able to mistake that for a date object that's useful for your purposes.

I conveniently skipped a part. You need to be able to define currentHelsinkiOffset. If you can use date.getTimezoneOffset() on the server side, or just use some if statements to describe when the time zone changes will occur, that should solve your problem.

Conclusion - I think especially for this purpose you should use a date library like moment-timezone.

While MomentJS is a great library, it may not provide a solution for every use case. For example, my server provides dates in UTC, and when the time portion of the date is not saved in the db (because it's irrelevant), the client receives a string that has a default time of all zeros - midnight - and ends with an offset of +0000. The browser then automatically adjusts for my local time zone and pulls the time back by a few hours, resulting in the previous day.

This is true with MomentJs as well.

One solution is to slice off the time portion of the string, and then use MomentJS as described in the other answers.

But what happens if MomentJS is not a viable option, i.e. I already have many places that use a JS Date and don't want to update so many lines of code? The question is how to stop the browser from converting dates based on local time zone in the first place. And the answer is, when the date is in ISO format, you cannot.

However, there is no rule that says the string you pass to JavaScript's Date constructor must be in ISO format. If you simply replace the - that separates the year, month, and day with a /, your browser will not perform any conversion.

In my case, I simply changed the format of the Dates server-side, and the problem was solved without having to update all the client-side JS dates with MomentJS.

Note that the MDN docs for JavaScript's Date class warn about unpredictable browser-behavior when parsing a string to create a Date instance.