GMT Offset to PHP timezone

[Shawazi]

Is it possible to have something like?

$offset = -5;
$timezone = getTimeZone($offset); //return America/New_York
date_default_timezone_set($timezone);

I know I can go the offset way with -5 * 3600 and whatnot, but that doesn't factor in daylight savings. I know that PHP handles it automatically in the more recent versions.

[Shawazi]

Wrote a function that should do the trick

function getTimeZoneDateTime($GMT, $timestamp=time()) {
	$timezones = array(
		'-12'=>'Pacific/Kwajalein',
		'-11'=>'Pacific/Samoa',
		'-10'=>'Pacific/Honolulu',
		'-9'=>'America/Juneau',
		'-8'=>'America/Los_Angeles',
		'-7'=>'America/Denver',
		'-6'=>'America/Mexico_City',
		'-5'=>'America/New_York',
		'-4'=>'America/Caracas',
		'-3.5'=>'America/St_Johns',
		'-3'=>'America/Argentina/Buenos_Aires',
		'-2'=>'Atlantic/Azores',// no cities here so just picking an hour ahead
		'-1'=>'Atlantic/Azores',
		'0'=>'Europe/London',
		'1'=>'Europe/Paris',
		'2'=>'Europe/Helsinki',
		'3'=>'Europe/Moscow',
		'3.5'=>'Asia/Tehran',
		'4'=>'Asia/Baku',
		'4.5'=>'Asia/Kabul',
		'5'=>'Asia/Karachi',
		'5.5'=>'Asia/Calcutta',
		'6'=>'Asia/Colombo',
		'7'=>'Asia/Bangkok',
		'8'=>'Asia/Singapore',
		'9'=>'Asia/Tokyo',
		'9.5'=>'Australia/Darwin',
		'10'=>'Pacific/Guam',
		'11'=>'Asia/Magadan',
		'12'=>'Asia/Kamchatka'
	);
	date_default_timezone_set($timezones[$GMT]); //ensures that whenever i return this date, i will get central time
	if ($GMT == -2) $timestamp -= 3600; //since i set that an hour ahead, im subtracting the extra hour now
	return date('Y-m-d H:i:s', $timestamp);
}