(FOMONTH or SOMONTH this is opposite to function EOMONTH in SQL SERVER)
CREATE FUNCTION [dbo].[FOMONTH] (@d date)returns dateASBegin
DECLARE @sd DATE
SET @sd = DATEADD(month, DATEDIFF(month, 0, @d ), 0)RETURN @sdend-- call it - > SELECT dbo.FOMONTH(GETDATE())