I am trying to output number of days between today and the date I enter so I have a problem I encounter error: "Warning: date_diff() expects parameter 2 to be DateTimeInterface" So what's the problem ?
Your problem lies in that when using
date_diff you have to make sure that you're comparing objects that are actual date objects. Also the return type for
date_diff is a DateInterval object. You're treating it as a string.
$today = new DateTime(); // $today is a DateTime object $date = new DateTime("2016-09-16"); // $date is also a DateTime object! $diff = date_diff($date,$today); // compare two objects of the same type FTW! echo $diff->days; // $diff is a DateInterval object, so echo it's 'days' property. // output: 3 (as of this writing)