Hi,
Um... that code would return the last day of the 9th month, not the 10th month.
I would do this:
DECLARE @mydate datetime
SET @mydate = '11/01/2000'
SELECT DAY(dateadd(dd,-1, @mydate))
to get the last day of a month (of October in this case). Note the lack of the second dateadd call.
Tom