php convert datetime to UTC

Php Problem Overview

I am in need of an easy way to convert a date time stamp to UTC (from whatever timezone the server is in) HOPEFULLY without using any libraries.

Php Solutions

Solution 1 - Php

Use strtotime to generate a timestamp from the given string (interpreted as local time) and use gmdate to get it as a formatted UTC date back.

Example

As requested, here’s a simple example:

echo gmdate('d.m.Y H:i', strtotime('2012-06-28 23:55'));

Solution 2 - Php

Using DateTime:

$given = new DateTime("2014-12-12 14:18:00");
echo $given->format("Y-m-d H:i:s e") . "\n"; // 2014-12-12 14:18:00 Asia/Bangkok

$given->setTimezone(new DateTimeZone("UTC"));
echo $given->format("Y-m-d H:i:s e") . "\n"; // 2014-12-12 07:18:00 UTC

Solution 3 - Php

Try the getTimezone and setTimezone, see the example

(But this does use a Class)

UPDATE:

Without any classes you could try something like this:

$the_date = strtotime("2010-01-19 00:00:00");
echo(date_default_timezone_get() . "<br />");
echo(date("Y-d-mTG:i:sz",$the_date) . "<br />");
echo(date_default_timezone_set("UTC") . "<br />");
echo(date("Y-d-mTG:i:sz", $the_date) . "<br />");

NOTE: You might need to set the timezone back to the original as well

Solution 4 - Php

Do this way:

gmdate('Y-m-d H:i:s', $timestamp)

or simply

gmdate('Y-m-d H:i:s')

to get "NOW" in UTC.

Check the reference:

http://www.php.net/manual/en/function.gmdate.php

Solution 5 - Php

If you have a date in this format YYYY-MM-HH dd:mm:ss, you can actually trick php by adding a UTC at the end of your "datetime string" and use strtotime to convert it.

date_default_timezone_set('Europe/Stockholm');
print date('Y-m-d H:i:s',strtotime("2009-01-01 12:00"." UTC"))."\n";
print date('Y-m-d H:i:s',strtotime("2009-06-01 12:00"." UTC"))."\n";

This will print this:

2009-01-01 13:00:00
2009-06-01 14:00:00

And as you can see it takes care of the daylight savings time problem as well.

A little strange way to solve it.... :)

Solution 6 - Php

Convert local time zone string to UTC string.
e.g. New Zealand Time Zone

$datetime = "2016-02-01 00:00:01";
$given = new DateTime($datetime, new DateTimeZone("Pacific/Auckland"));
$given->setTimezone(new DateTimeZone("UTC"));
$output = $given->format("Y-m-d H:i:s"); 
echo ($output);

NZDT: UTC+13:00
if $datetime = "2016-02-01 00:00:01", $output = "2016-01-31 11:00:01";
if $datetime = "2016-02-29 23:59:59", $output = "2016-02-29 10:59:59";
NZST: UTC+12:00
if $datetime = "2016-05-01 00:00:01", $output = "2016-04-30 12:00:01";
if $datetime = "2016-05-31 23:59:59", $output = "2016-05-31 11:59:59";

https://en.wikipedia.org/wiki/Time_in_New_Zealand

Solution 7 - Php

If you don't mind using PHP's DateTime class, which has been available since PHP 5.2.0, then there are several scenarios that might fit your situation:

If you have a $givenDt DateTime object that you want to convert to UTC then this will convert it to UTC:
```
$givenDt->setTimezone(new DateTimeZone('UTC'));
```
If you need the original $givenDt later, you might alternatively want to clone the given DateTime object before conversion of the cloned object:
```
$utcDt = clone $givenDt;
$utcDt->setTimezone(new DateTimeZone('UTC'));
```
If you only have a datetime string, e.g. $givenStr = '2018-12-17 10:47:12', then you first create a datetime object, and then convert it. Note this assumes that $givenStr is in PHP's configured timezone.
```
$utcDt = (new DateTime($givenStr))->setTimezone(new DateTimeZone('UTC'));
```
If the given datetime string is in some timezone different from the one in your PHP configuration, then create the datetime object by supplying the correct timezone (see the list of timezones PHP supports). In this example we assume the local timezone in Amsterdam:
```
$givenDt = new DateTime($givenStr, new DateTimeZone('Europe/Amsterdam'));
$givenDt->setTimezone(new DateTimeZone('UTC'));
```

Solution 8 - Php

I sometime use this method:

// It is not importnat what timezone your system is set to.
// Get the UTC offset in seconds:
$offset = date("Z");

// Then subtract if from your original timestamp:
$utc_time = date("Y-m-d H:i:s", strtotime($original_time." -".$offset." Seconds"));

Works ~~all~~ MOST of the time.

Solution 9 - Php

As strtotime requires specific input format, DateTime::createFromFormat could be used (php 5.3+ is required)

// set timezone to user timezone
date_default_timezone_set($str_user_timezone);

// create date object using any given format
$date = DateTime::createFromFormat($str_user_dateformat, $str_user_datetime);

// convert given datetime to safe format for strtotime
$str_user_datetime = $date->format('Y-m-d H:i:s');

// convert to UTC
$str_UTC_datetime = gmdate($str_server_dateformat, strtotime($str_user_datetime));

// return timezone to server default
date_default_timezone_set($str_server_timezone);

Solution 10 - Php

http://php.net/manual/en/function.strtotime.php or if you need to not use a string but time components instead, then http://us.php.net/manual/en/function.mktime.php

Solution 11 - Php

With PHP 5 or superior, you may use datetime::format function (see documentation http://us.php.net/manual/en/datetime.format.php)

 echo strftime( '%e %B %Y' , 
	date_create_from_format('Y-d-m G:i:s', '2012-04-05 11:55:21')->format('U')
	);	// 4 May 2012

Solution 12 - Php

try >echo date('F d Y', strtotime('2010-01-19 00:00:00'));

will output: > January 19 2010

you should change format time to see other output

Solution 13 - Php

General purpose normalisation function to format any timestamp from any timezone to other. Very useful for storing datetimestamps of users from different timezones in a relational database. For database comparisons store timestamp as UTC and use with gmdate('Y-m-d H:i:s')

/**
 * Convert Datetime from any given olsonzone to other.
 * @return datetime in user specified format
 */

function datetimeconv($datetime, $from, $to)
{
    try {
        if ($from['localeFormat'] != 'Y-m-d H:i:s') {
            $datetime = DateTime::createFromFormat($from['localeFormat'], $datetime)->format('Y-m-d H:i:s');
        }
        $datetime = new DateTime($datetime, new DateTimeZone($from['olsonZone']));
        $datetime->setTimeZone(new DateTimeZone($to['olsonZone']));
        return $datetime->format($to['localeFormat']);
    } catch (\Exception $e) {
        return null;
    }
}

Usage:

> $from = ['localeFormat' => "d/m/Y H:i A", 'olsonZone' => 'Asia/Calcutta']; > > $to = ['localeFormat' => "Y-m-d H:i:s", 'olsonZone' => 'UTC']; > > datetimeconv("14/05/1986 10:45 PM", $from, $to); // returns "1986-05-14 17:15:00"

Solution 14 - Php

As an improvement on Phill Pafford's answer (I did not understand his 'Y-d-mTG:i:sz' and he suggested to revert timezone). So I propose this (I complicated by changing the HMTL format in plain/text...):

<?php
header('content-type: text/plain;');
$my_timestamp = strtotime("2010-01-19 00:00:00");

// stores timezone
$my_timezone = date_default_timezone_get();
echo date(DATE_ATOM, $my_timestamp)."\t ($my_timezone date)\n";

// changes timezone
date_default_timezone_set("UTC");
echo date("Y-m-d\TH:i:s\Z", $my_timestamp)."\t\t (ISO8601 UTC date)\n";
echo date("Y-m-d H:i:s", $my_timestamp)."\t\t (your UTC date)\n";

// reverts change
date_default_timezone_set($my_timezone);
echo date(DATE_ATOM, $my_timestamp)."\t ($my_timezone date is back)\n";	
?>

Solution 15 - Php

alternatively you can try this:

<?php echo (new DateTime("now", new DateTimeZone('Asia/Singapore')))->format("Y-m-d H:i:s e"); ?>

this will output :

> 2017-10-25 17:13:20 Asia/Singapore

you can use this inside the value attribute of a text input box if you only want to display a read-only date.

remove the 'e' if you do not wish to show your region/country.

Solution 16 - Php

Follow these steps to get UTC time of any timezone set in user's local system (This will be required for web applications to save different timezones to UTC):

Javascript (client-side):

 var dateVar = new Date();
 var offset = dateVar.getTimezoneOffset();
 //getTimezoneOffset - returns the timezone difference between UTC and Local Time
 document.cookie = "offset="+offset;

Php (server-side):

 public function convert_utc_time($date)
 {
 	$time_difference = isset($_COOKIE['offset'])?$_COOKIE['offset']:'';
 	if($time_difference != ''){
 		$time = strtotime($date);
 		$time = $time + ($time_difference*60); //minutes * 60 seconds
 		$date = date("Y-m-d H:i:s", $time);
 	} //on failure of js, default timezone is set as UTC below
 	return $date;
 }
 ..
 ..
 //in my function
 $timezone = 'UTC';
 $date = $this->convert_utc_time($post_date); //$post_date('Y-m-d H:i:s')
 echo strtotime($date. ' '. $timezone)

Content Type	Original Author	Original Content on Stackoverflow
Question	Jeremey	View Question on Stackoverflow
Solution 1 - Php	poke	View Answer on Stackoverflow
Solution 2 - Php	joerx	View Answer on Stackoverflow
Solution 3 - Php	Phill Pafford	View Answer on Stackoverflow
Solution 4 - Php	Attilio	View Answer on Stackoverflow
Solution 5 - Php	Johan	View Answer on Stackoverflow
Solution 6 - Php	Frank Hou	View Answer on Stackoverflow
Solution 7 - Php	The Coprolal	View Answer on Stackoverflow
Solution 8 - Php	aorcsik	View Answer on Stackoverflow
Solution 9 - Php	Christos Pontikis	View Answer on Stackoverflow
Solution 10 - Php	psychotik	View Answer on Stackoverflow
Solution 11 - Php	MUY Belgium	View Answer on Stackoverflow
Solution 12 - Php	StevieJ	View Answer on Stackoverflow
Solution 13 - Php	Sandeep	View Answer on Stackoverflow
Solution 14 - Php	7Tonin	View Answer on Stackoverflow
Solution 15 - Php	Bruce Tong	View Answer on Stackoverflow
Solution 16 - Php	Pradeep Kumar	View Answer on Stackoverflow