Welcome to WebmasterWorld Guest from

Forum Moderators: open

Message Too Old, No Replies

Unix timestamp TO date with offset



11:36 am on Apr 13, 2012 (gmt 0)

10+ Year Member

Hello All -

Brain-wracking issue here.

I've got a PHP-generated UNIX timestamp that I feed to a javascript function. This function then formats and displays the date to the user.

For example, the timestamp 1335024000 equals April 22, 2012 - 12:00:00 am - 00:00 and the javascript function I wrote spits out "22 Apr". Perfect.

That is, it's perfect for users in my timezone (Manila, Philippines).

If the user is in New York City, (I've tested this by re-setting the timezone on my computer to (UTC-05:00) Eastern Time) the php time stamp stays the same, but Javascript spits out "21 Apr". Arg!

Here's my javascript code:

var months = ['Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec'];
var stamp = 1335024000;
var a = new Date(stamp*1000);
var date = a.getDate();
var month = months[a.getMonth()];

I've investigated getTimezoneOffset() and, it does give a -5 hour offset from UTC, but I don't understand how to alter my code to accommodate this offset.

Will getTimezoneOffset() correct this issue? If not, how does one deal with this issue?

All guidance greatly appreciated.

alert(date + ' ' + month);

Okay, so javascript is doing something based upon the users timezone settings.

I've studied


1:56 pm on Apr 13, 2012 (gmt 0)

WebmasterWorld Senior Member fotiman is a WebmasterWorld Top Contributor of All Time 5+ Year Member Top Contributors Of The Month

The JavaScript Date constructor that you're using is passing in the the number of milliseconds since 1 January 1970 00:00:00 UTC.

Lets calculate the difference.

var jan_1_1970 = new Date(1970, // year
0, // month
1, // day
0, // hour
0, // minute
0, // second
0); // millisecond
var apr_22_2012 = new Date(2012,
var difference = apr_22_2012.getTime() - jan_1_1970.getTime();
// difference = 1335049200000 != 1335024000000

In other words, your stamp value is incorrect. It is off by 7 hours.
1335049200000 - 1335024000000 = 25200000 ms
25200000ms / 1000 = 25200 seconds
25200 s / 60 = 420 minutes
420 m / 60 = 7 hours


1:54 am on Apr 16, 2012 (gmt 0)

10+ Year Member

Fotiman -

Thanks very much for your reply.

That's very unusual as the time stamp I'm using always keeps coming up with the same result as I had posted initially UNLESS I change the php timezone ini setting. This is something I'm going to have to investigate further on the php forum.

At any rate, I have found a work-around which yields the correct date display no matter what timezone the users system clock is set to.

Thanks again for your guidance.


Featured Threads

Hot Threads This Week

Hot Threads This Month