Hours in time slots

Hi,

I basically have Start time and End time.

I need to calculate how many hours belong to specific time slot 06-18, 18-22 and 22-06.

Example:

Start        End

06:27:00 14:28:00
06:27:00 15:28:00
06:29:00 14:28:00
10:58:00 19:03:00
10:58:00 19:03:00
13:30:00 21:33:00
13:30:00 22:33:00
21:55:00 05:55:00
06:22:00 14:31:00
06:22:00 14:31:00

Do you have any idea how to calculate this?

Any help is very appreciated.