How to calculate the contents of a coloumn, where there are empty cells

[nje]

Good Evening
In the Wheelchair 1, 2, 3 & 4 sheets in the attached workbook, I would like to do a simple calculation of the contents of column 'H'.
Instead of it adding up to just a few £'s I'm getting the result of something like -£5880.00.
I think I know whay is wrong, but I don't know the solution to it.
Column 'H' populates when a date is put into Column 'E'
So if cells if cells in Column 'E' are empty then column 'H' doesn't do the sum.

What I think I need is a bit of formula to put into column 'H' to tell it to ignore blank spaces and count what is there.
Can someone advise please?
Thanks

[p24leclerc]

instead of using this custom format "£"# ##0.00;; in columns H and O,
use the following fomrat "£"# ##0.00
It will show you have some errors in your formula. Correct your formula and it should be OK.

[ron2k_1]

your problem is in F7. You don't have an ending date:
Change from:
=INT((E7+1-D7)/7)
to
=IF(E7="",0,INT((E7+1-D7)/7))

[nje]

Thank you both for your contribution.
Ron2k_1 I'm very pleased that you could identify the problem with the formula and that you could give me a solution which I have used and it solved the issue.
Thanks

p24leclerc, thank you also, I wasn't sure what was wrong with the formulas, but with hindsight it was the one Ron2k_1 has pointed out to me.
I did however change the formatting of the cells to your suggested format and although I don't know what the difference in the format means, everything seems to work ok.