Wsrtjtyk

An even simpler method looks like this:

date_default_timezone_set('Europe/London'); // your user's timezone

$my_datetime='2013-10-23 15:47:10';

echo date('Y-m-d H:i:s',strtotime("$my_datetime UTC"));

As described in the PHP manual, strtotime() accepts a timezone too, you just have to append it to your datetime.

I recommend you to store all your datetimes in UTC because that way you won't have problems with the daylight savings.

This worked for me and it's pretty clean too!

function convert_to_user_date($date, $format = 'n/j/Y g:i A', $userTimeZone = 'America/Los_Angeles', $serverTimeZone = 'UTC')

{

    try {

        $dateTime = new DateTime ($date, new DateTimeZone($serverTimeZone));

        $dateTime->setTimezone(new DateTimeZone($userTimeZone));

        return $dateTime->format($format);

    } catch (Exception $e) {

        return '';

    }

}



function convert_to_server_date($date, $format = 'n/j/Y g:i A', $userTimeZone = 'America/Los_Angeles', $serverTimeZone = 'UTC')

{

    try {

        $dateTime = new DateTime ($date, new DateTimeZone($userTimeZone));

        $dateTime->setTimezone(new DateTimeZone($serverTimeZone));

        return $dateTime->format($format);

    } catch (Exception $e) {

        return '';

    }

}



//example usage

$serverDate = $userDate = '2014-09-04 22:37:22';

echo convert_to_user_date($serverDate);

echo convert_to_server_date($userDate);

None of these answers worked for me (I skipped trying code that was overly bulky in size). I also think it's weird to change the default timezone just for a single conversion.

Here is my solution:

function changeTimeZone($dateString, $timeZoneSource = null, $timeZoneTarget = null)

{

  if (empty($timeZoneSource)) {

    $timeZoneSource = date_default_timezone_get();

  }

  if (empty($timeZoneTarget)) {

    $timeZoneTarget = date_default_timezone_get();

  }



  $dt = new DateTime($dateString, new DateTimeZone($timeZoneSource));

  $dt->setTimezone(new DateTimeZone($timeZoneTarget));



  return $dt->format("Y-m-d H:i:s");

}

So, to convert to the server default, you would just pass one timezone:

changeTimeZone("2016-10-24 16:28", "Asia/Tokyo");

To convert from the server default to the user, you would leave the 2nd parameter null or blank:

changeTimeZone("2016-10-24 16:28", "", "Asia/Tokyo");

And to switch between to timezones unrelated to the default, you would provide 2 timezones:

changeTimeZone("2016-10-24 16:28", "America/New_York", "Asia/Tokyo");

DateTime::setTimezone -- date_timezone_set — Sets the time zone for the DateTime object

Object oriented style

<?php

$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";

?>

Procedural style

<?php

$date = date_create('2000-01-01', timezone_open('Pacific/Nauru'));

echo date_format($date, 'Y-m-d H:i:sP') . "n";



date_timezone_set($date, timezone_open('Pacific/Chatham'));

echo date_format($date, 'Y-m-d H:i:sP') . "n";

?>

The above examples will output:

2000-01-01 00:00:00+12:00

2000-01-01 01:45:00+13:45

UTC to local:

<?php

$datetime = date("Y-m-d H:i:s");

$utc = new DateTime($datetime, new DateTimeZone('UTC'));

$utc->setTimezone(new DateTimeZone('America/Sao_Paulo'));

echo $utc->format('Y-m-d H:i:s');



?>

// Convert date from one zone to another..
/*
$zone_from='Asia/Kolkata';

$zone_to='America/Phoenix';



date_default_timezone_set($zone_from);



$convert_date="2016-02-26 10:35:00";



echo $finalDate=zone_conversion_date($convert_date, $zone_from, $zone_to);



*/

function zone_conversion_date($time, $cur_zone, $req_zone)

{   

    date_default_timezone_set("GMT");

    $gmt = date("Y-m-d H:i:s");



    date_default_timezone_set($cur_zone);

    $local = date("Y-m-d H:i:s");



    date_default_timezone_set($req_zone);

    $required = date("Y-m-d H:i:s");



    /* return $required; */

    $diff1 = (strtotime($gmt) - strtotime($local));

    $diff2 = (strtotime($required) - strtotime($gmt));



    $date = new DateTime($time);

    $date->modify("+$diff1 seconds");

    $date->modify("+$diff2 seconds");



    return $timestamp = $date->format("Y-m-d H:i:s");

}

<?php

$time='6:02';

$dt = new DateTime($time, new DateTimeZone('America/New_York'));

//echo $dt->format('Y-m-d H:i:s') . PHP_EOL;

$dt->setTimezone(new DateTimeZone('Asia/Kolkata'));

echo $dt->format('H:i') . PHP_EOL; 

?>