First and Last Day of Current Month in SQL Server

use tempdb

DECLARE @mydate DATETIME

SELECT @mydate = GETDATE()

SELECT CONVERT(VARCHAR(25),DATEADD(dd,-(DAY(@mydate)),@mydate),101),'Last Day of Previous Month'

UNION ALL

SELECT CONVERT(VARCHAR(25),DATEADD(dd,-(DAY(@mydate)-1),@mydate),101) AS Date_Value,'First Day of Current Month' AS Date_Type

UNION ALL

SELECT CONVERT(VARCHAR(25),@mydate,101) AS Date_Value, 'Today' AS Date_Type

UNION ALL

SELECT CONVERT(VARCHAR(25),DATEADD(dd,-(DAY(DATEADD(mm,1,@mydate))),DATEADD(mm,1,@mydate)),101),'Last Day of Current Month'

UNION ALL

SELECT CONVERT(VARCHAR(25),DATEADD(dd,-(DAY(DATEADD(mm,1,@mydate))-1),DATEADD(mm,1,@mydate)),101),'First Day of Next Month'