Calculating with Time - subtract

[MrVaux76]

Hi there

Hope someone can help me with this, since I am really stuck.

I have these 2 variables:

$end
$duration

Both of these comes in a HH:MM:SS format (24 hour clock)

I need to subtract the $duration from the $end so I get the $start.

I am getting all kind of weird results, even negative results.

Example:

$end = 22:10:25
$duration = 37:45:28 (I know the days are changing here, but I have no interest in displaying that.)

The $start should then be calculated to 08:24:57 - That I can´t get to Work


Anyone who knows how to do this? 

 

[CroNiX]

What have you tried? Have you tried using the DateTime interface?

http://php.net/manual/en/class.datetime.php

[grissom]

Try this http://php.net/manual/en/datetime.sub.php  but be careful if you are subtracting time around the switchover of daylight saving and read the notes on the page carefully. Good luck !