PHP DateTime Update

I'm using PHP > 5.3 and i have a question in respect of DateTime: 
First i'm not able to use:
$date   = new DateTime('2012-06-08 00:00:00');
$t = $date->createFromFormat('Y/m/d', '2012-06-11 23:59:59');
I get the following error message:
      Call to undefined method DateTime::createFromFormat()
I can use other function in that class.
The second thing i'm puzzled about how to update the object initial date, or do i have to create a new object?

Answer:

createFromFormat is a static method of DateTime so you would need to call it like:
$t = DateTime::createFromFormat('Y-m-d', '2012-06-11');
You can update the initial $date object by doing:
$date = DateTime::createFromFormat('Y-m-d', '2012-06-11');

http://stackoverflow.com/questions/10998331/php-datetime-update?answertab=votes#tab-top