date_default_timezone_set() function to set default time zone of server

Set the default timezone for the current script

date_default_timezone_set() changes the default timezone used by date/time functions in the current request.

date_default_timezone_set('Asia/Kolkata');
echo date('Y-m-d H:i:s T');

Use a valid timezone identifier such as Asia/Kolkata rather than a fixed numeric offset when daylight-saving rules may matter.

Irrespective of time zone set in php.ini file , we can set the time zone of the server for our script by using date_default_timezone_set() function.
The list of applicable time zone identifier is available here.
Here is the sample code to set the time zone.

<?Php
echo date_default_timezone_set();
?>

We can set it like this

date_default_timezone_set('America/Chicago');

After setting the time zone , you can read the same by using date_default_timezone_get() function.

Setting the time zone in php.ini file

You can set the default time zone at php.ini file. If you are using for first time then search for the line saying

;date.timezone =

Change it to

date.timezone ="Asia/Calcutta";

You can change the area as per your requirement by using time zone identifier .

Example: Dynamically Switching Time Zones

date_default_timezone_set('America/New_York');
echo date('Y-m-d H:i:s').'<br>'; // Output: Current time in New York
date_default_timezone_set('Asia/Kolkata');
echo date('Y-m-d H:i:s'); // Output: Current time in Kolkata

Output

2026-09-29 22:48:46
2026-09-30 08:18:46

Example: Listing All Available Time Zones

$timezones = timezone_identifiers_list();
print_r($timezones);

Or to display as list

$timezones = timezone_identifiers_list();
foreach($timezones as $key=>$value){
	echo "$key : $value".'<br>';
}

Creating a dropdown list for user selection of Timezone

PHP Date Functions date_default_timezone_get() get the time zone

Subhendu Mohapatra

Author & Instructor at plus2net

I write and maintain practical tutorials on Python, PHP, SQL, JavaScript, HTML, jQuery, and web development at plus2net. The tutorials focus on clear explanations, working examples, and code that readers can test and adapt while learning.

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