subtract dates to include start date

[graemel]

HI,

Basically, in my work, we work out holidays in weekly blocks, so if I put the start date as e.g. 25/8/10 and the end date as 31/8/10, I want to be able to subtract it so it gives 7 days, rather than 6, so I can divide the result by 7 to give its weekly value (1 week).

I've got it to work by adding '+1' into the formula, but that's no use when some cells are blank as that would just leave the formula of 1/7 and give 0.143......, which then messes up the rest of my spreadsheet.

Any ideas would be appreciated.

Thanks.

[contaminated]

What about this one

=IF(COUNTA(A1:B1),B1-A1+1,0)

Where A1 start date and B1 is end date

[graemel]

Thanks for your reply. That works ok if I want the number of holidays days, as it produces the result of '7' for days when there are holidays and no value when there is are no holidays, but when I want to convert that to a weekly value, by dividing by 7, it correctly gives the value of '1' for 7 days, but as you can't divide 7 by 0 I get the error message #DIV/0! when I fill the rest of the cells with the formula.