php time between two times code example

Example 1: calculate time difference php

$time1 = new DateTime('09:00:59');
$time2 = new DateTime('09:01:00');
$interval = $time1->diff($time2);
echo $interval->format('%s second(s)');

Result: 1 second(s)

Example 2: difference between two timestamps php

$datetime1 = new DateTime('2016-11-30 03:55:06');//start time
$datetime2 = new DateTime('2016-11-30 11:55:06');//end time
$interval = $datetime1->diff($datetime2);
echo $interval->format('%Y years %m months %d days %H hours %i minutes %s seconds');//00 years 0 months 0 days 08 hours 0 minutes 0 seconds