Count Blocks of occurances within a range

Hello All,

This is my first posting here. I have a problem I have been trying to solve for some weeks now.

I have a sheet for recording staff sickness etc. I can count the number of days a member of staff is sick or late in a range, but i need to count the number of periods of sick in the same range.

I have attached an example. In cell AB4 i want to count the number of Periods of sick (3 in this case) - in order that later I can calculate bradford factor.

I would really be very grateful for some pointers or guidance guys.

Thank you!

Andy Brown