Calculate time

[Meelkoppie]

Hi, can someone please help me with a formula to calculate time. I created a formula, but the problem is, it also calculated duplicate time. For example:

John's Overtime for task A: 19h05 to 21h15 = 2 hours and 10 min
John's Overtime for task B: 20h00 to 21h30 = 1 hours and 30min

Total hours = 3 hours and 40 min which is incorrect. It must exclude part time for task B, because it overlap with task A. The correct hours must be 2 hours and 25 min.

I will appreciate it very much if someone can help me.

Thank you very much.

Meelkoppie

 

[Ormus]

Colomn A has the start time (format hh:mm)
Colomn B has the end time (format hh:mm)

Colomn C and copy down, place: =IF(A2>B1,B2-A2,B2-B1). This will give 02:10 for the first row and 00:15 for the 2nd row. Sum of the 2 gets to 02:25