SQL Server: Get First and Last Days Of Month

DECLARE @min DATETIME

DECLARE @max DATETIME

DECLARE @now DATETIME

SET @now = GETDATE();

--get first day of last month:

SET @min = CONVERT(VARCHAR(25),DATEADD(dd

,-(DAY(DATEADD(mm,1,@now))-1),DATEADD(mm,-1,@now)),101) 

--get the last day of last month

SET @max = CONVERT(VARCHAR(25),DATEADD(dd

,-(DAY(@now)),@now),101) 

--get the first day of current month

SET @min = CONVERT(VARCHAR(25),DATEADD(dd

,-(DAY(@now)-1),@now),101)  

--get the last day of current month

SET @max = CONVERT(VARCHAR(25),DATEADD(dd

,-(DAY(DATEADD(mm,1,@now))),DATEADD(mm,1,@now)),101)