What formula to calculate periods??

I'd be so grateful if anybody could help with the below query.......

A7:A82 = Dept.
B7:B82 = Employee name
C7:C82 = Total hours sick
D7:D82 = Hours sick for Tuesday 01/01/2013
E7:E82 = Hours sick for Wednesday 02/01/2013
F7:F82 = Hours sick for Thursday 03/01/2013
G7:G82 = Hours sick for Friday 04/01/2013
H7:H82 = Hours sick for Monday 07/01/2013

all the way through to IY7:IY82 Tuesday 24/12/2013. Weekends are excluded.

Here is the query, what formula can I use to add up the "periods" or "episodes" of sickness. So, If the sick period was 01/02/13 all the way through to the 09/02/13......this would be 1 period, but if the sick period was 18/03/13 to the 21/03/13, then again on 15/07/13 and again from 11/12/13 to the 19/12/13.....altogether this would be 3 periods.
Is this a COUNT formula?

Many thanks in advance!

Send me dummy data.....

As requested.....

=SUMPRODUCT(--(C7:IX7=0),--(D7:IY7<>0))+(D7<>0)

this works a treat for the first original upload spreadsheet.