Week Wise Stored Procedure

This is how i have optimized and its working good.If i am doing anything wrong please suggest the alternate

USE [WH4_2008]
GO
/****** Object:  StoredProcedure [dbo].[Production_WeekSplit]    Script Date: 01/03/2015 17:21:41 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO

ALTER PROCEDURE [dbo].[Production_WeekSplit]
@monthparam int, @yearparam int
AS
BEGIN
        SET NOCOUNT ON;

select CONVERT(varchar(50),CAST(DATEADD(wk,datediff(wk,0,Date),0) as Date)) + ' ' + '-' + ' ' + CONVERT(varchar(50),CAST(DATEADD(wk,datediff(wk,0,Date),0) + 6 as Date))  as 'Date Range',SUM(Plan1) as Plan1,
SUM(Actual) as Actual,SUM(Variance) as Variance
From Production
Where MONTH(Date) = @monthparam
AND YEAR(Date) = @yearparam
Group by CONVERT(varchar(50),CAST(DATEADD(wk,datediff(wk,0,Date),0) as Date)) + ' ' + '-' + ' ' + CONVERT(varchar(50),CAST(DATEADD(wk,datediff(wk,0,Date),0) + 6 as Date))
END