Timezone conversion in php

Can anyone suggest an easy method to convert date and time to different timezones in php?

You can use the datetime object or their function aliases for this:

Example (abridged from PHP Manual)

date_default_timezone_set('Europe/London');

$datetime = new DateTime('2008-08-03 12:35:23');
echo $datetime->format('Y-m-d H:i:s') . "\n";
$la_time = new DateTimeZone('America/Los_Angeles');
$datetime->setTimezone($la_time);
echo $datetime->format('Y-m-d H:i:s');

---

Edit regarding comments

> but i cannt use this method because i need to show date in different time zones as the user login from different locations

That's not a problem. When a user logs in, you determine his timezone and set it to your DateTime object just like shown. I'm using a similar approach in one of my projects and it works like a charm.

> in the database i need to get the dates in any single timezone, then only it can be processed properly

You store the time either as a timestamp or a datetime in one timezone. When you query a DateTime field, you either convert the time in a DateTime object to this timezone or - if your db supports it - query with the selected timezone.

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 2 timezones unrelated to the default, you would provide 2 timezones:

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

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');

?>

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

// 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; 
?>

I always struggle to remember how exactly setTimezone() method works. Is it adjusting datetime according to timezone? Or does it take a given datetime, drops its timezone, and uses the one you pass? All in all, I'd rather have a more intuitive way to work with timezones.

I like this one:

(new AdjustedAccordingToTimeZone(
    new DateTimeFromISO8601String('2018-04-25 15:08:01+03:00'),
    new Novosibirsk()
))
    ->value();

It outputs a datetime in ISO8601 format, in Novosibirsk timezone.

This approach uses meringue library, check out a quick start for more examples.