Depends on how you have each day set up.
If you have a daily cell value with hours in it you could use something
like:

If Range("A1:A7").value <>"" then msgbox "The Employee has worked 7 days
straight."
' Where A1:A7 is the hrs worked for each day.

Corey....

Patrick

This checks for series of 7 dates in a column:

=(2*MIN(B1:B7)+6)/2*7=SUM(B1:B7)

As in:
Row\Col       A (Date)     B (Ans)
1     25/1/2007    TRUE
2     26/1/2007    FALSE
3     27/1/2007    FALSE
4     28/1/2007    FALSE
5     29/1/2007    FALSE
6     30/1/2007    FALSE
7     31/1/2007    FALSE
8                FALSE
9     2/2/2007    TRUE
10    3/2/2007    FALSE
11    4/2/2007   
12    5/2/2007   
13    6/2/2007   
14    7/2/2007   
15    8/2/2007   

You can then just do a
=if(countif(B:B,TRUE)>0,"Worked more than 6 days in a row","")

Otherwise do the same in VBA.

There are a number of ways to do this. How is your data laid out? How many
columns wide is the data? What does the data in each column mean? Are
non-worked days blanks or do they have a 0?

There are many way to lay out a timesheet, and a solution that applied to
one format may not work in another. You need to supply much more
information. Details count.