On Thu, 20 May 2010 14:57:01 -0700, Siralec
wrote:

User enters a specific date, I'd like to round that entry to the end of the
month

=A1-DAY(A1)+32-DAY(A1-DAY(A1)+32)

If it needs to be done in the SAME cell as the entry, you could use a VBA Event
triggered macro.
--ron