Calculate Work hours between date range based on Odd/Even weeks

Hi all.

I have a somewhat small problem that I just can't seem to wrap my head around.
I hope some of you Excel GURU's can help

What I am trying to do is the following: I have an employee work schedule where it is possible to register when an employee starts and ends vacation.
The Plan is for document to be able to calculate how many hours the person is away, that in itself is easy enough.
Where my troubles start, is that some employees have different schedules, depending on whether it is an odd or even week.

Example: An employee starts vacation 01-01-2014 and ends his vacation 08-01-2014
the result should be 35 hours and 45 min. since the 1, 2 and 3 is in an odd week and the 6, 7, and 8 is in an even week.

Is it possible to make a formula that can check if the start/end dates and the dates in between is in an odd/even week and then calculate the correct no. of hours?

I have attached an example and hope some of you can help me solve this problem

Thanks in advance.


Sincerely

Kenneth Andersen