Try something like this:

With
A1: (a date)
B1: (number of weeks to increment)

This formula adds the number of weeks in cell B1 to the date in A1 and
returns the Friday of that week
C1: =A1-WEEKDAY(A1)+B1*7+6

Does that help?
***********
Regards,
Ron

XL2002, WinXP


"SSJ" wrote:

Hello!

How can I add, say 12 weeks, to a date to arrive at a date at the end of week 12.

Thanks in advace
SJ