How to setOffset() in joomla 3.2.3

Question

I am migrating a component from joomla 2.5 to joomla 3.2, I got an error in the method where am using setOffset

//old version used in joomla 2.5 

$data->setOffset(JFactory::getConfig()->get('offset'));

I referred the Link : http://docs.joomla.org/Potential_backward_compatibility_issues_in_Joomla_3_and_Joomla_Platform_12.2

//after i  refered the above link i changed my code  like 

if($date === null ) {   
  $date = JFactory::getDate();
  $tz = JFactory::getConfig()->get( 'offset' );

  // new Version 
  $date->setTimezone($tz);

  $date = $date->format( "%Y-%m-%d" );
}

but i am getting an error -

DateTime::getTimezone() expects exactly 0 parameters, 1 given  /example.php on line 5 .

Plz need your solution to fix the error

Answer 1

Finally I found the solution for this Error by passing the object of DateTimeZone as a parameter (notice the $date->setTimezone(new DateTimeZone($tz)); in the code bellow). It's working fine.

if($date === null )
{
  $date = JFactory::getDate();
  $tz = JFactory::getConfig()->get( 'offset' );

  $date->setTimezone(new DateTimeZone($tz)); //here!

  $date = $date->format( "Y-m-d" );
}