It works if A1 has the formula date(2008,2,1) and just the month in the
formula changes.

I have link on the date so that the month links to a cell and the user just
adds 1 to the value in the cell.

"Rick Rothstein (MVP - VB)" wrote:

End of Period:

=A1+39-DAY(A1+32)-WEEKDAY(A1+32-DAY(A1+33))

I do not believe this formula works all the time. Unless I am wrong, it
fails for dates like 2/28/2008 through 3/1/2008, 3/29/2008 through 4/1/2008,
4/29/2008 through 5/1/2008, and so on.

Rick