I've got some case statements in my analytics query that I want to return something different based on a date being last week or last month.  I can do this week or this month using absweek() and absmonth().  if i do these -1 though it just removes a day form the date.  I can -7 to get last week but for last month there isn't a constant number that will work.  Does anyone know a way of using these functions to identify last week or last month please?

e.g. 

case when absweek (today()) = absweek(deals."Sold Date") then 1 else 0 end as 'This Week Sale'

case when absweek (today()-7) = absweek(deals."Sold Date"-7) then 1 else 0 end as 'Last Week Sale'