// Get a list of all time zones $timeZones = DateTimeZone::listIdentifiers(); // Loop through the time zones and print them out foreach ($timeZones as $zone) { echo $zone . "\n"; } // Get a list of time zones in the Africa region $africaZones = DateTimeZone::listIdentifiers(DateTimeZone::AFRICA); // Loop through the Africa time zones and print them out foreach ($africaZones as $zone) { echo $zone . "\n"; }In the first example, we simply call the listIdentifiers method with no parameters to get a list of all time zones recognized by the system. We then loop through the resulting array and print out each time zone. In the second example, we pass the `DateTimeZone::AFRICA` constant as a parameter to the listIdentifiers method to get a list of time zones in the Africa region. We then loop through this array and print out each time zone. It is difficult to determine the specific package library being used without more information on the codebase, but it is likely to be a built-in PHP library.