How to do calculation (Time Difference) in PHP

otixz

Good day...
I'm wondering if anyone can help me with my problem:
I'm doing a shift maintenance program in PHP:

Given:
1.) Time in
2.) Time out

Rule: Working hours must not me less or more than 9 hrs.

Situation:
1.) whenever I try to add a shift within hours in a day (example 00:00:
00 to 23:00:00) its ok.

Example:
a.) 09:00:00 and 18:00:00 - since the difference is 9 hours, the program will execute correctly.
b.) 14:00:00 - 23:00:00 - since the difference is 9 hours, the program will execute correctly.

PROBLEM:
1.) When I tried adding 23:00:00 to 08:00:00 (11PM to 8AM shift), I cannot add this shift because the time difference is 15 Hours. But what I want to intend is its correct time difference which is 9 hours....

Can anyone please help me with this problem?
I'm really having trouble with this....

Thank you in advance!

Grace

NogDog

The first thing that comes to mind would be to compare the start time to the end time, and if start time is greater than end time then add 24 hours to the end time:

$timeWorked = ($startTime < $endTime) ? $endTime - $startTime : 24 + $endTime - $startTime ;

otixz

Wow! Great logic!!!!

Thank you very much for the advice and fast reply Sir!
I'll take this one and see how I can do it.

If you do not mind, I would really appreciate it if you would give some pointers on how can I put your logic into codes.

Thank you very much once again!

Grace