Get week start date and week end date of a month in SQL server

#First week of particular month will be start from 1st day of month and last week of month will be end at month end date    

    with C(i) as

              ( select CONVERT(VARCHAR(10),CAST(@monthStart as datetime),111) i

                UNION ALL

                select CONVERT(VARCHAR(10),DATEADD (day,1,i),111) i from C

                     where DATEADD (day,1,i)

                             <DATEADD(month,1,@monthStart)

              ), C1 as

              (

              select DATEPART(WEEK,i)-DATEPART(WEEK,@monthStart)+1 WeekOfMonth,i from C

              )

              select WeekOfMonth,min(i) StartDate, max(i) EndDate from C1 group by WeekOfMonth