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 canĀ“t get to Work Anyone who knows how to do this?