(PHP 5 >= 5.1.0, PHP 7, PHP 8)
date_default_timezone_set — Sets the default timezone used by all date/time functions in a script
date_default_timezone_set() sets the default timezone used by all date/time functions.
Instead of using this function to set the default timezone in your script, you can also use the INI setting date.timezone to set the default timezone.
timezoneId
       The timezone identifier, like UTC,
       Africa/Lagos, Asia/Hong_Kong, or
       Europe/Lisbon. The list of valid identifiers is
       available in the Список підтримуваних часових поясів.
      
   This function returns false if the
   timezoneId isn't valid, or true
   otherwise.
  
Приклад #1 Getting the default timezone
<?php
date_default_timezone_set('America/Los_Angeles');
$script_tz = date_default_timezone_get();
if (strcmp($script_tz, ini_get('date.timezone'))){
    echo 'Script timezone differs from ini-set timezone.';
} else {
    echo 'Script timezone and ini-set timezone match.';
}
?>
