Calendar Slicer - Only Display Selectable Months with Data

Anonymous, try this:

Two fact tables:

Sales_US

Sales_Other

Create a calculated table:

SalesDates = 
VAR DatesUS =
    SELECTCOLUMNS ( Sales_US, "Date", Sales_US[Date] )
VAR DatesOther =
    SELECTCOLUMNS ( Sales_Other, "Date", Sales_Other[Date] )
VAR DatesAll =
    UNION ( DatesUS, DatesOther )
VAR DatesDistinct =
    DISTINCT ( DatesAll )
RETURN
    DatesDistinct

Join the calculated table to the date table:

Create matrix. The row field should be Date from the date table (not the calculated table).

Create slicer using the calculated table.