My code is giving me the error "Fatal error: Call to a member function sub() on string" As you can see the $date variable is a string based on the echo, but it still believes it to be a string.
My code:
echo $stringDate;
//PRINTS "2014-03-27"
$date = date('yyyy-mm-dd', strtotime( $stringDate );
echo $date;
//PRINTS "14141414-0303-2727"
$date->sub(new date_interval_create_from_date_string('70 days') );
//Produces "Fatal error: Call to a member function sub() on string"
$milestones["Method Development Checklist"]['date'] = $date;