Convert DateInterval object to seconds in php

Question

$datetime1 = date_create('2009-10-11');
$datetime2 = date_create('2009-10-13');
$interval = date_diff($datetime1, $datetime2);

How do i convert the above $interval to seconds in php

Answer 1

Another way to get the number of seconds in an interval is to add it to the zero date, and get the timestamp of that date:

$seconds = date_create('@0')->add($interval)->getTimestamp();

This method will handle intervals created via the DateInterval contructor more or less correctly, whereas shiplu's answer will ignore years, months and days for such intervals. However, shiplu's answer is more accurate for intervals that were created by subtracting two dates. For intervals consisting only of hours, minutes and seconds, both methods will get the correct answer.