This may also help
To calculate hours on a dailty basis, when finish time is after 24:00, use the following:
Format cells to HH:mm
Cell A1 is Start Time
Cell B1 is Finish Time
=IF(B1-A1>0,(B1-A1),(B1-A1)+1)
It works for me in Excel & Works when total time is less than 24 hours.
Hope this helps and makes sense.
Cheers,
