How to make a report to display next 18 months of data with when user select a particular month from the filter in power pivot tabular model.

Question

Hi,
i have a  dimension table  with month_key having values (201201,201202,201203.......202011,202012) and month name ( Jan 12, feb 12,......NOV 20, Dec 20)  and a fact  table with columns (month_key ,measure_types, Amount)
My requirement is to create a power pivot report  in which when a user select a month from the filter, the report should display the (selected month+18 ) month's data against each type . when JAN 12 is selected ,the jan 2012 +18 = june 2013
, month name should be populated with months till june 2013 only .
i tried creating calculated column"END DATE " in the fact table with  dax expression to calculate the 18th monh from the current month  as below 
month_key END DATE
201201       201306    
201202       201307      
and thought of filtering the table with month key <= ENDDATE but it is not working as expected. could you please guide me on this ? Is there any time intelligence function that serve the purpose . Iam using  excel 2010
..hence could not do any calculation on the report side also. please suggest .
Thanks in advance                                                                                                                                               

Answer 1

Do you need to show the measure calculated for those 18 months as a total on 1 row, or do you need to select a single month and then display on row filters 18 distinct rows?
The first is trivial as driezl has suggested.
The second will require a second calendar table.
I created this example workbook for a coworker who had a similar problem. You will have to use the disconnected table as your filter and pull your related table onto the rows.
Finally, the easiest way to deal with the sort of date arithmetic you need to do is to restructure your date table to have a series of "Sequential" fields. These fields should be the number of units of time since the beginning of your calendar.
For example, consider a calendar starting on January 1, 2010. For January - December 2010, [MonthSequential] = 1, 2, ..., 12. For January - December 2011, [MonthSequential] = 13, 14, ..., 24, and so on, incrementing by 1 for each sequential month in time.
Assuming you have this set up in your date tables (one related to your model - DimDate - and one disconnected - DisconDimDate) your measure would look like this:
18 Month Measure:=
CALCULATE( [Measure]
, FILTER( DimDate
, DimDate[MonthSequential] >= MAX( DisconDimDate[MonthSequential] )
&& DimDate[MonthSequential] <= MAX( DisconDimDate[MonthSequential] ) + 18
Please review this example along with the workbook I have linked above.