SQL Server 2005 Get First and Last date for any Month in any Year

Question

I have a stored procedure that has to accept a month as int (1-12) and a year as int. Given those two values, I have to determine the date range of that month. So I need a datetime variable to represent the first day of that month, and another datetime variable to represent the last day of that month. Is there a fairly easy way to get this info?

Answer 1

First day of the month: SELECT DATEADD(mm, DATEDIFF(mm, 0, GETDATE()), 0)

Last day of the month: SELECT DATEADD(ms, -3, DATEADD(mm, DATEDIFF(m, 0, GETDATE()) + 1, 0))

Substitute a DateTime variable value for GETDATE().

I got that long ago from this very handy page which has a whole bunch of other date calculations, such as "Monday of the current week" and "first Monday of the month".