Get the most recent Friday's date SQL

Question

I\'m trying to get the most recent Friday in SQL Server 2008.

I have this. It gets the beginning of the week (monday) then subtracts 3 days to get Friday.

Answer 1

DECLARE @date DATETIME = '20110512' -- Thursday
SELECT DATEADD(DAY,-(DATEDIFF(DAY,'19000105',@date)%7),@date) --20110506

SET @date = '20110513' -- Friday
SELECT DATEADD(DAY,-(DATEDIFF(DAY,'19000105',@date)%7),@date) --20110513

SET @date = '20110514' -- Saturday
SELECT DATEADD(DAY,-(DATEDIFF(DAY,'19000105',@date)%7),@date) --20110513

1. Calculate the number of days between a known Friday (05 Jan 1900) and the given date
2. The remainder left from dividing the difference in 1. by 7 will be the days elapsed since the last Friday
3. Subtract the remainder in 2. from the given date