The perfect TimeZone selectbox list for PHP 5.3+

timezone.php

<?php
$regions = array(
    'Africa' => DateTimeZone::AFRICA,
    'America' => DateTimeZone::AMERICA,
    'Antarctica' => DateTimeZone::ANTARCTICA,
    'Asia' => DateTimeZone::ASIA,
    'Atlantic' => DateTimeZone::ATLANTIC,
    'Australia' => DateTimeZone::AUSTRALIA,
    'Europe' => DateTimeZone::EUROPE,
    'Indian' => DateTimeZone::INDIAN,
    'Pacific' => DateTimeZone::PACIFIC
);

$timezones = array();
foreach ($regions as $name => $mask)
{
    $zones = DateTimeZone::listIdentifiers($mask);
    foreach($zones as $timezone)
    {
		// Lets sample the time there right now
		$time = new DateTime(NULL, new DateTimeZone($timezone));

		// Us dumb Americans can't handle millitary time
		$ampm = $time->format('H') > 12 ? ' ('. $time->format('g:i a'). ')' : '';

		// Remove region name and add a sample time
		$timezones[$name][$timezone] = substr($timezone, strlen($name) + 1) . ' - ' . $time->format('H:i') . $ampm;
	}
}


// View


echo '<label>Select Your Timezone</label>';
echo '<select name="timezone">';
foreach($timezones as $region => $list)
{
	echo '<optgroup label="' . $region . '">' . "\n";
	foreach($list as $timezone => $name)
	{
		if($user_timezone_db_entry == $timezone)
		{
			echo '<option SELECTED value="' . $timezone . '">' . $name . '</option>' . "\n";
	 	}
		 else
		 {
			echo '<option value="' . $timezone . '">' . $name . '</option>' . "\n";
		 }
	}
	echo '<optgroup>' . "\n";
}
echo '</select>';

This has been updated to include Australia, and fix the Asia spelling mistake.

Also fixed it so you can get the name of the text to be stored easily (and received) when using a database.

You'll see on line 43 "$user_timezone_db_entry".
Get this value from your DB if you are storing the TZs as a text value.
Of course, if you are using INT for the TZ and they are all stored in a separate table, then this example won't work for you.

A millions thanks, this is awesome and I'll apply it! <3