Find out Week Start date and Week End date

SELECT	DATENAME(WEEKDAY, GETDATE()) AS DayName,
	DATEADD(DAY, DATEDIFF(DAY, '19000101', GETDATE()) / 7 * 7, '19000101') AS WeekStartDate,
	DATEADD(DAY, DATEDIFF(DAY, '19000101', GETDATE()) / 7 * 7, '19000107') AS WeekEndDate;

SELECT	DATENAME(WEEKDAY, GETDATE()) AS DayName,
	DATEADD(dd, 1 - DATEPART(dw, GETDATE()), GETDATE()) AS WeekStartDate,
	DATEADD(dd, 7 - DATEPART(dw, GETDATE()), GETDATE()) AS WeekEndDate;

DayName	WeekStartDate	         WeekEndDate
Tuesday	2015-03-30 00:00:00.000	2015-04-05 00:00:00.000

DayName	WeekStartDate	         WeekEndDate
Tuesday	2015-03-29 19:13:17.477	2015-04-04 19:13:17.477