SQL Server 2005: how to subtract 6 month

Question

I have a date, suppose today date

declare @d datetime
set @d = \'20101014\'

I need

select @d - 
<         


        

Answer 1

You can use DATEADD:

select DATEADD(month, -6, @d)

EDIT: if you need the number of days up to 6 months ago you can use DATEDIFF:

select DATEDIFF(day, @d, DATEADD(month, -6, @d))