Adding work hours based on particular start or finish times

I am trying to automate the calculation of hours worked from Mon to Fri if a shift starts before a given time, or finishes after a given time.
The spreadsheet is attached.
I really have no idea where to start with it.

Thanks

Maybe you could do something with this...

=IF(ISBLANK(C3),"",IF(OR(C3<TIME(7,0,0),D3>TIME(18,0,0)),1,""))

This will return a 1 if the start or finish time is before or after 07:00 & 18:00

Windy

Hi Windy,
Thank you for the reply.
I am working on the same theory, I substitute the 1 at the end of your formula with the cell reference, from the hours of the shift and this will give me the hours that attract the shift penalty.
It does mean having another set of cells to match the roster lines and days but it does work.

Thank you