PHP get current local time based on GMT offset

Question

There is a function date_default_timezone_set() in php which accepts timezone string like "UK/London". But unfortunately I have the GMT offset of the user only.

Let's say I am on GMT +5 and I want to get current time based on GMT +5. I did a lot of search on google but did not help.

Since, I do not have the time zone string I am looking for something like

$current_date = date("Y M D H:S, "GMT +5");

Please help

possible duplicate of [How do I get Greenwich Mean Time in PHP?](http://stackoverflow.com/questions/851574/how-do-i-get-greenwich-mean-time-in-php) — NorthBridge, Apr 22 '14 at 09:07
@NorthBridge, the offset is strange there, I don't want offset like $offset=4*60*60; — Shahid Karimi, Apr 22 '14 at 09:11
@Sarah Why not? It is fairly easy to convert your GMT +5 to 5*60*60 isn't it? — Andresch Serj, Apr 22 '14 at 09:13
Since the timezones are not likely to change, you can maybe hardcode an array with the GMT offset as a key and the timezone string (UK/London) as a value and call date_default_timezone_set() ? — Alexandre Nucera, Apr 22 '14 at 09:13
@AlexandreN. That will probably not work, since if the offset is key, it will have to be a multidimensional array (there are many timezone strings for each offset), and things will get nasty. — NorthBridge, Apr 22 '14 at 09:15
@Alexandre No, you cannot. GMT offsets change all the time! (Unintentionally punny?) — deceze, Apr 22 '14 at 09:15
I don't care if GMT offset gets changes all the time. I just need a solution, @deceze — Shahid Karimi, Apr 22 '14 at 09:20

score 3 · Accepted Answer · edited Apr 22 '14 at 09:41

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You can only exclusively use GMT offsets for right now, i.e. it's completely useless if the user told you his GMT offset half a year ago and you want to know now what time it is at his location. It could basically be anything within a range of a few hours. Even if you got the offset a few seconds ago, it may already be different by the time you do the calculations if you happen to hit a DST change exactly.

Having said that, you'll want to add/subtract the offset hours from the formatted time, which is really the only thing you can do.

$offset = 5;
$hours  = (gmdate('H') + $offset) % 24;

echo $hours . gmdate(':i:s Y m d');

That's just an example, you'll need to handle minute offsets as well.

edited Apr 22 '14 at 09:41

NorthBridge

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answered Apr 22 '14 at 09:13

deceze

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You just posted a too complex answer – Shahid Karimi Apr 22 '14 at 09:16
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Meaning what? You want a simpler function? You don't understand what I wrote? – deceze Apr 22 '14 at 09:17
@decceze, see the next answer. :D – Shahid Karimi Apr 22 '14 at 09:30

score 2 · Answer 2 · answered Apr 22 '14 at 09:27

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date_default_timezone_set('GMT');
$curTime = strtotime("+5 hours");
$current_date = date("Y M D H:S, $curTime);

set GMT timezone first or get GMT offset。
get timestamp
timestamp to date

answered Apr 22 '14 at 09:27

davidnkcao

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PHP get current local time based on GMT offset

2 Answers2