I have one field that is using "WINDOW_SUM" to display a running YTD total where the first month is in December of the previous calendar year. (Rolling Sum )
Now I want to filter on the year, but I want to make sure that if they chose, for example, 2016, that the date values returned include all of 2016, but also December of the previous year so that I get the correct starting point.
Is this possible?
Don't filter on the year directly. Give the user a parameter to choose the year, and then use a calc to grab 13 months.
Maybe something like this:
IF YEAR(date field) = [Year Parameter] or
(year(date field) = [Year Parameter]-1 AND month(date field)=12)
then 1 else 0 end
Put that on the filter shelf and select for 1.