Question

How can i reverse the following so that it displays the date again:

19th March 2012 should give you a week_ref of: 5855

EDIT: this is the correct line:

DATEDIFF(DAY, 0, Start_Week) / 7 AS week_ref   -- create the unique week reference number

Answer 1

Like this:

select dateadd(wk, 5855, 0) 

or this:

select dateadd(wk,DATEDIFF(DAY, 0, Start_Week) / 7, 0)

EDIT:

WHERE DATEDIFF(DAY, 0, Start_Week) / 7 = 5855

Validation test here:

SELECT 1  WHERE DATEDIFF(DAY, 0, getdate()) / 7 = 5855