Rolling 12 Month

Hi all
I am trying to monitor days over a rolling 12 month period so that I can see on a day by day basis the total number of holidays taken from one day to the next ie. 19/1/06 to 19/1/07. I have a sheet with the dates in column A with either a 1 or a 0 in column B with 1 meaning holiday taken on that date.
Eg

A B C
1st 0 =today()-5
2nd 1 =total hols
3rd 1
4th 0
5th 1
6th 1
7th 1
8th 0
9th 0
10th 0

Lets say todays date is the 10th, that would mean I would like to sum the total hols taken between the 5th and the 10th,because of Today()-5, which would =3. If today was the 7th the total would be 5. Obviously Today()-5 would become -365 for the year. I have a formula in C2=IF((A5=C1),SUM(B5:B10),0), but this is only looking at one date cell (A5). I would like to count all the holidays back from the current date and put the result in C2.
I hope anyone can understand what I am trying to achieve. If further clarification is needed please say.
Thanks