Working out hours

[jaiD]

Hi All,

I'm trying to work out how I could calculate the following:-

Data in my excel sheet is:- Sarah 9.00 - 5.00, Mary 9.00-2.00, James 9.00-5.00

I'd like to work out how many staff are in at say 10.00 Oc'lock which would be 3

or How many staff are in at 4.00 which would be 2, is there any calcuation which would do this.

Thanks in Advance for any suggestions