Calculate total seconds in PHP DateInterval

Question

What is the best way to calculate the total number of seconds between two dates? So far, I've tried something along the lines of:

$delta   = $date->diff(new DateTime('now'));
$seconds = $delta->days * 60 * 60 * 24;

However, the days property of the DateInterval object seems to be broken in the current PHP5.3 build (at least on Windows, it always returns the same 6015 value). I also attempted to do it in a way which would fail to preserve number of days in each month (rounds to 30), leap years, etc:

$seconds = ($delta->s)
         + ($delta->i * 60)
         + ($delta->h * 60 * 60)
         + ($delta->d * 60 * 60 * 24)
         + ($delta->m * 60 * 60 * 24 * 30)
         + ($delta->y * 60 * 60 * 24 * 365);

But I'm really not happy with using this half-assed solution.

Answer 1

You could just put in the hard numbers (instead of 60*60 - put in 3600) so it doesn't need to calculate them each time.

Edit - fixed the number based off your comment.

Answer 2

You could do it like this:

$currentTime = time();
$timeInPast = strtotime("2009-01-01 00:00:00");

$differenceInSeconds = $currentTime - $timeInPast;

time() returns the current time in seconds since the epoch time (1970-01-01T00:00:00), and strtotime does the same, but based on a specific date/time you give.

Answer 3

Could you not compare the time stamps instead?

$now = new DateTime('now');
$diff = $date->getTimestamp() - $now->getTimestamp()