date_timezone_get($object)

<?php
   date = date_create("25-09-1989");res = date_timezone_get(date);timeZone_name = timezone_name_get(res);
   print("Timezone: ".timeZone_name);
?>

Timezone: UTC

<?php
   tz = new DateTimeZone("Indian/Mahe");date = date_create("25-09-1989", tz);res = date_timezone_get(date);
   print_r(res);
?>

DateTimeZone Object
(
    [timezone_type] => 3
    [timezone] => Indian/Mahe
)

<?php
   tz = new DateTimeZone("Indian/Mahe");date = date_create("25-09-1989", tz);res = date_timezone_get(date);timeZone_name = timezone_name_get(res);
   print("Timezone: ".timeZone_name);
?>

Default timezone: Indian/Mahe

<?php
   echo "Old time zone is ". date_default_timezone_get();
   timeZone = 'America/Costa_Rica';

   if( date_default_timezone_set(timeZone) ){
      # Now get this time zone.
      echo "New time zone is ". date_default_timezone_get();
   }
?>

Old time zone is America/Denver
New time zone is America/Costa_Rica