create or alter proc dbo.Test 
    @Date date
  , @WeekCount int
as
	with cteData ( WeekNum )
	as (
		select 0
		
		union all
		
		select WeekNum + 1
		from cteData
		where WeekNum < @WeekCount - 1
	)
	select dateadd(day, WeekNum * 7, @Date) as Date
	from cteData
	order by WeekNum
	option (maxrecursion 10000) -- 10000 - это максимальное число строк которое может вернуть процедура, замените если надо.
go

exec dbo.Test
    @Date = '2013-03-06'
  , @WeekCount = 4