There a tow different ways in PHP you can solve your problem. Just use the date and time related extensions like this:
date_default_timezone_set('Europe/Berlin');
$datetime = new DateTime("now");
// result: Thu Oct 24 2013 16:34:14 Europe/Berlin+0200 (CEST)
echo $datetime->format("D M d Y H:i:s eO (T)");
The second example solving your problem:
$timezone = new DateTimeZone('Asia/Calcutta');
$datetime = new DateTime("now", $timezone);
// result: Thu Oct 24 2013 20:04:14 GMT+0530
echo $datetime->format("D M d Y H:i:s \G\M\TO");
For further examples just have a look for the php time and date related objects and functions: http://www.php.net/manual/en/book.datetime.php