On Tue, 8 Jan 2008 16:06:35 -0800 (PST), SteveM wrote...

Bret it's not clear to me which is the input data.

Well, now it's getting interesting. You both guys (Steve, Max) point me
out in the right direction. But thanks to my awkward explanation i got
you confused ;-(( Sorry for that. The solution however is near but not
right on the nail!

The input data is the starttime and finishtime of the timeperiod (that's
just a workshift) for example
StTime 17:00
FiTime 01:00

Now, the other data available are the slottimes:
TimeSlot 1 - 6:00-8:00
TimeSlot 2 - 8:00-18:00
TimeSlot 3 - 18:00-22:00
TimeSlot 4 - 22:00-6:00
These are just periods when working unsocial hours.

Now I need to determine WHAT PART of the time period (the shift) falls
in whatever timeslot. The part should be the result.

For clearity:
The INPUT Max uses in his sample
Denoting TimePeriods.xls
should be the RESULT (the output) i'm looking for.

Conclusion, I get the point of your examples but it doesn't give me the
result i'm looking for. But as mentioned earlier that's the result of my
bad explanation of the problem :o))
Really appreciate your help and i think we can tackle this pesky
problem.

--
With kind Regards,
Bret Bernever