$date = new DateTime('2017-02-09T00:20:00+05:00');
var_dump($date);
object(DateTime)[367]
public 'date' => string '2017-02-09 00:20:00.000000' (length=26)
public 'timezone_type' => int 1
public 'timezone' => string '+05:00' (length=6)
$date->setTimezone(new DateTimeZone('Europe/Moscow'));
var_dump($date);
object(DateTime)[367]
public 'date' => string '2017-02-08 22:20:00.000000' (length=26)
public 'timezone_type' => int 3
public 'timezone' => string 'Europe/Moscow' (length=13)