Count based on calendar value in context

[#1]

Hi,

I am new to Qlikview and are about to create my first app. I am trying to understand set analysis but the concept is not fully clear to me yet. Hopefully someone can give me a little help.

I have a fact table with data from a table. I have a period for when the row is valid (start and stop-date) and I have a DueDate. I have linked the fact-table to a calendar (using a linked table in between). Works fine. Now my problem is to write the set expression to only count the number of rows that are within a certain period considering the context.

For example how can I write an expression to only count distinct where delayed is between 0 and 3 months? In my example I would like to get my first record in January 2017. I have tried something like this to just count all delayed: COUNT({<DueDate<MAX(Date)>}DISTINCT _ID)