Claus - your formula is absolutely brilliant! I applied =SUM(C10:C16)-COUNTIF(C10:C16,""&6)*0.5 to cells C17 to K17.. I did attach the excel sheet zipped but I can't remember now if it was before I made those changes or not.

There is one problem with the formula though :( That is, it is not removing the overtime hours. There is no overtime, it becomes like hmm "floating hours". So when I applied the formula to E17, it showed his paid hours as 43, when technically if you minus the break & the overtime, he only has 39.

So when it calculates his gross salary, its adding in those 4 extra hours.
I changed your formula to: =SUM(E10:E16)-COUNTIF(E10:E16,""&6)*0.5 - (F17) and it seems to function properly. What do you think of the above, is it correctly done?

I have two questions:

1 - Overtime column(Friday).. formula is: =IF(C148.16,(C14-8.16),"")
next weeks Friday is: =IF(E147.5,(E14-7.5),"")
These days alternate each week, but always the same. I get the same error on both: Error: The formula in this cell differs from the formulas in this area of the spreadsheet. Is this actually an error of its it just a notification?

2 - When I sum the overtime columns to total in D17, etc, I get the Error: The formula in this cell differs from the formulas in this area of the spreadsheet. Is this actually an error of its it just a notification?

well I'm going to try the zipped file again hope it works this time. :)