Get the First Day of the month
CREATE FUNCTION [dbo].[udf_GetFirstDayOfMonth] ( -- Add the parameters for the function here @Date datetime ) RETURNS datetime AS BEGIN -- Declare the return variable here DECLARE @ResultVar datetime -- Add the T-SQL statements to compute the return value here SELECT @ResultVar = CONVERT(VARCHAR(10),DATEADD(dd,-(DAY(@Date)-1),@Date),120) -- Return the result of the function RETURN @ResultVar END