date_timezone_set(object,timezone)

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

Timezone: Indian/Mahe

<?php
   date = new DateTime("25-09-1989", new DateTimeZone('Indian/Mahe'));res = date_timezone_set(date, timezone_open("Indian/Kerguelen"));     print("Timezone: ".timezone_name_get(date_timezone_get(date)) );
?>

Timezone: Indian/Kerguelen

<?php
   dateSrc = '2007-04-19 12:50 GMT';dateTime = date_create( dateSrc);DateTimeZone = timezone_open ( 'America/Chicago' );
   date_timezone_set( dateTime,DateTimeZone );
   NewDateTimeZone = date_timezone_get(dateTime);   
   echo 'New timeZone is '. timezone_name_get(NewDateTimeZone);
   echo "\n";
   # Using second function.dateTime = new DateTime(dateSrc);DateTimeZone = timezone_open ( 'America/Chicago' );
   dateTime->setTimezone(DateTimeZone );
   NewDateTimeZone =dateTime->getTimezone ();   
   echo 'New timeZone is '. timezone_name_get ($NewDateTimeZone);
?>

New timeZone is America/Chicago
New timeZone is America/Chicago