9

From a DateTime object, I am interested in getting the time in different TimeZones. As explained in the DateTime::setTimezone doc, this works pretty well when the DateTime object is created from a string:

$date = new DateTime('2000-01-01', new DateTimeZone('Pacific/Nauru'));
echo $date->format('Y-m-d H:i:sP') . "\n";

$date->setTimezone(new DateTimeZone('Pacific/Chatham'));
echo $date->format('Y-m-d H:i:sP') . "\n";

$date->setTimezone(new DateTimeZone('UTC'));
echo $date->format('Y-m-d H:i:sP') . "\n";

echo $date->getTimestamp() . "\n";

The above examples will output:
2000-01-01 00:00:00+12:00
2000-01-01 01:45:00+13:45
1999-12-31 12:00:00+00:00
946641600

Now is the interesting part: If we pick up our timestamp, and initiate our DateTime Object with it following the manual instructions.

$date2 = new DateTime('@946641600');

$date2->setTimezone(new DateTimeZone('Pacific/Nauru'));
echo $date2->format('Y-m-d H:i:sP') . "\n";

$date2->setTimezone(new DateTimeZone('Pacific/Chatham'));
echo $date2->format('Y-m-d H:i:sP') . "\n";

$date2->setTimezone(new DateTimeZone('UTC'));
echo $date2->format('Y-m-d H:i:sP') . "\n";

echo $date2->getTimestamp() . "\n";

And here we get: // [edit] humm... Sorry, this output is wrong...
1999-12-31 12:00:00+00:00
1999-12-31 12:00:00+00:00
1999-12-31 12:00:00+00:00
946641600

UTC forever !!! We cannot change the timezone anymore !?!

Is it PHP or is it me ? Version 5.3.15

hakre
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mika
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    Aren't you supposed to specify a timezone on instantiation with the timestamp? – Dennis Haarbrink Oct 17 '12 at 13:50
  • Am getting a different result here http://codepad.viper-7.com/zAv8dz – Baba Oct 17 '12 at 13:59
  • It works fine on version 5.3.15 ....... – Baba Oct 17 '12 at 14:06
  • @Dennis Haarbrink he does not have to do that .. that is why he i using `setTimezone` – Baba Oct 17 '12 at 14:07
  • Dammit. It's me :/ @Baba you are right. It just works fine. Thanks ! – mika Oct 17 '12 at 14:13
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    @Dennis - Documentation mentions you cannot set timezone in the constructor, it's going to be ignored. Now the set_timezone method works fine, if you use it properly :) – mika Oct 17 '12 at 14:17
  • I'll just say that I have been burn by this stuff to. And there is absolutely no reason why it is made that way, this is some retarded thinking. From billions of ways you can specify date in DateTime constructor you will always get create date time with current time zone, with the very rare super exception of timestamps. Ofc this will never get fixed because - backward compatibility. – morphles Aug 01 '13 at 11:00

2 Answers2

7

Ok, so I was getting mad by myself. Of course, I am the one to be wrong...
To get it straight, I'll just pick up the bits that are relevants in the doc here and here.
Manual says:

// Using a UNIX timestamp.  Notice the result is in the UTC time zone.
$date = new DateTime('@946684800');
echo $date->format('Y-m-d H:i:sP') . "\n";

So indeed, you can use setTimezone to get times again in your timezone (which could be expected if your system is set up that way !):

$timezone = new DateTimeZone('Europe/Madrid');
$date->setTimezone(new DateTimeZone('Pacific/Chatham'));

Note that 

$date =  new DateTime('@1306123200', new DateTimeZone('Europe/Madrid'));

is misleading, since you will be in UTC anyways ! (and yes, it is very clearly specified in the constructor's doc. So be careful ;)

Thanks @hakre Thanks all !

mika
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  • If what you need is a date (corresponding to your timezone) in mysql format, you can also use the following straight away: $mysql_time = date("Y-m-d H:i:s", $ts_time); – mika Feb 20 '13 at 11:45
4

It's just you. As far as PHP is concerned, it's all fine and dandy, PHP manual covers this nicely: http://www.php.net/manual/en/datetime.construct.php

hakre
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