Sickness Analysis

The following is based on you starting in cell C20 and copying the conditional formatting to the rest of the calendar...
=C20=INDEX(All_Staff,MATCH($G$7,INDEX(All_Staff,0,1)),MATCH(C20,INDEX(All_Staff,MATCH($G$7,INDEX(All_Staff,0,1)),0)))

Basically it finds the row for that employee and sees if that cell's date is in the row of data for that employee.

Thanks for your speedy reply, really appreciate you looking at this! However when i input your formula into conditional formatting into cell C20 as advised the error of "You may not use unions, intersections, or array constants for conditional formatting criteria" . Any suggestions on why this error would appear or am I doing something wrong here?
This was tested in office 2007 however it will be used within a 2003 environment if that makes any difference.
Again really appreciate it!