total hours between 2 dates

Hi great helpers,
I want to add the numbers of hours in a 4 week period. I have used the following formula (from this site) to total according to month but I don't seem to be able to adapt it to change it to only add hours between 2 dates or for the 28 day period. Can you help please. I thought maybe I should be using a SUMIF but I can't get that happening either.

I have attached a simple file( I think!!)

=SUMPRODUCT((TEXT($B$3:$B$61,"mm/yy")="07/07")*($C$3:$D$61))

thanks in anticipationSUMIF questionxls.xls

Thanks for replying so promptly.

I can total for a month by name, but I need to total hours for 28 day period starting from 14/7/08. The 28 day period may go into the next month.
maztaz

Hi protonLeah
I hope I didn't offend with my short answer yesterday. Didn't mean to but I failed to see the attachment and the great little gadget. Thankyou - very handy. What do you call the 'slider' so I can learn about how to do it.

I feel I may have to experiment with DATE functions to sum for a given number of days or between two dates.
thanks again for your help
maztaz

Try =SUMPRODUCT( ($A$3:$A$30 >= "7/14/08" + 0) * ($A$3:$A$30 <= "7/14/08" + 27) * $B$3:$B$30)

Thanks for that formula. I got a value error at first but changed the date format and it works a treat.

thanks again to both helpers.

maztaz

It ay be simpler if you put the start date in a cell, e.g. in Cell E2 put the date 14-Jul-08 and then use shg's suggested formula adapted as follows:

=SUMPRODUCT( ($A$3:$A$30 >= E2) * ($A$3:$A$30 <E2 + 28) * $B$3:$B$30)

In this way you can more easily change the date period

I agree with DLL, except the 28 should be 27 for a 28-day period.

.....but I used < 28 rather than <=27 so it comes to the same thing

I just kinda missed that ...

That is indeed more intuitive.

Thanks for the interest DLL. I'll try your version too. Trying to work out formulae when you're on your own with no training is hard. I don't understand much of the lingo. I really appreciate the gurus at this site
Thanks again