How do I find the hour difference between two dates in PHP?

I have two dates, formated like "Y-m-d H:i:s". I need to compare these two dates and figure out the hour difference.

You can convert them to timestamps and go from there:

$hourdiff = round((strtotime($time1) - strtotime($time2))/3600, 1);

Dividing by 3600 because there are 3600 seconds in one hour and using round() to avoid having a lot of decimal places.

You can use DateTime class also -

$d1= new DateTime("06-08-2015 01:33:26pm"); // first date
$d2= new DateTime("06-07-2015 10:33:26am"); // second date
$interval= $d1->diff($d2); // get difference between two dates
echo ($interval->days * 24) + $interval->h; // convert days to hours and add hours from difference