date_diff() expects parameter 1 to be DateTimeInterface, string given

Question

They have the same format:

$date_expire = '2014-08-06 00:00:00';
$date1 = date("Y-m-d G:i:s");
$date2 = date_create($date_expire);

$diff = date_diff($date1, $date2); //this line makes error.

But I am getting this error:

date_diff() expects parameter 1 to be DateTimeInterface, string given

Answer 1

Because you are passing string whereas date_diff expects datetime object,

$date_expire = '2014-08-06 00:00:00';    
$date = new DateTime($date_expire);
$now = new DateTime();

echo $date->diff($now)->format("%d days, %h hours and %i minuts");

DEMO.

Answer 2

<?php
$todays_date = date("m/d/Y H:i:s"); 

$exp = date("m/d/Y H:i:s", strtotime('+365 days',$todays_date));

// must use the date_create(); function
$int = date_diff(date_create($todays_date), date_create($exp));

// result, Time difference in days.
echo " time difference"." ".$int->format('%a'); 
?>