如何在PHP中为不同时区设置时间设置？

Question

I made a project with PHP that was expected to run inside my country Iran that its timezone is UTC+3:30. I inserted the line below inside my codes:

date_default_timezone_set('Asia/Tehran');

But now, I think it may be used by others from different countries. As a part if this project contains users signin logs, I must set the time matual with their country timezones.
How can I do it?

Answer 1

Here is how you can set the timezone:

<?php
session_start();
if(!isset($_SESSION['timezone']))
{
    if(!isset($_REQUEST['offset']))
    {
    ?>
    <script>
    var d = new Date()
    var offset= -d.getTimezoneOffset()/60;
    location.href = "<?php echo $_SERVER['PHP_SELF']; ?>?offset="+offset;
    </script>
    <?php    
    }
    else
    {
        $zonelist = array('Kwajalein' => -12.00, 'Pacific/Midway' => -11.00, 'Pacific/Honolulu' => -10.00, 'America/Anchorage' => -9.00, 'America/Los_Angeles' => -8.00, 'America/Denver' => -7.00, 'America/Tegucigalpa' => -6.00, 'America/New_York' => -5.00, 'America/Caracas' => -4.30, 'America/Halifax' => -4.00, 'America/St_Johns' => -3.30, 'America/Argentina/Buenos_Aires' => -3.00, 'America/Sao_Paulo' => -3.00, 'Atlantic/South_Georgia' => -2.00, 'Atlantic/Azores' => -1.00, 'Europe/Dublin' => 0, 'Europe/Belgrade' => 1.00, 'Europe/Minsk' => 2.00, 'Asia/Kuwait' => 3.00, 'Asia/Tehran' => 3.30, 'Asia/Muscat' => 4.00, 'Asia/Yekaterinburg' => 5.00, 'Asia/Kolkata' => 5.30, 'Asia/Katmandu' => 5.45, 'Asia/Dhaka' => 6.00, 'Asia/Rangoon' => 6.30, 'Asia/Krasnoyarsk' => 7.00, 'Asia/Brunei' => 8.00, 'Asia/Seoul' => 9.00, 'Australia/Darwin' => 9.30, 'Australia/Canberra' => 10.00, 'Asia/Magadan' => 11.00, 'Pacific/Fiji' => 12.00, 'Pacific/Tongatapu' => 13.00);
        $index = array_keys($zonelist, $_REQUEST['offset']);
        $_SESSION['timezone'] = $index[0];
    }
}
date_default_timezone_set($_SESSION['timezone']);

//rest of your code goes here
?>

Source

But I recommend not to do that. It would be better to set GMT (or your timezone) as default and change the information from the logs according the current timezone of each user when it is displayed.

Answer 2

Try this:

<?php
$fmt = new IntlDateFormatter("fa_IR@calendar=persian", IntlDateFormatter::FULL, IntlDateFormatter::FULL, 'Asia/Tehran', IntlDateFormatter::TRADITIONAL);
echo $fmt->format(time());
?>