date-util.php

<?php

/**
 *
 * Retrieves the date, in specified timezone and format.
 *
 * @param int|string $timestamp Unix timestamp.
 * @param string     $timezone  GMT Offset or timezone string to output result in.
 * 								E.G. +0400 or Asia/Dubai, +0630 or Asia/Dhaka etc.
 * @param string     $format    Optional. PHP date format.
 *
 * @return string|false 		  The date. False on invalid timestamp input.
 */
function datetime_utc_offset( $timestamp, $timezone, $format = 'Y-m-d H:i:s' ) {
	$timezone = new DateTimeZone( $timezone );

	//$datetime = date_create( '@' . $timestamp );

	try {
		if ( is_numeric( $timestamp ) ) {
			$timestamp = '@' . $timestamp;
		}

		$datetime = new Datetime( $timestamp );
		$datetime->setTimezone( $timezone );

		return $datetime->format( $format );
	} catch ( Exception $e ) {
		return false;
	}
}