// QueryAndChart — first and last sale date measures
// Paste into Power BI Desktop: Modeling > New measure, one measure at a time.
// Tables: Sales (Month, Category, Units, Revenue), Calendar (Date).
// Relationship: Calendar[Date] (one) to Sales[Month] (many), single direction.
First Sale Date =
FIRSTDATE (
    Sales[Month]
)

Last Sale Date =
LASTDATE (
    Sales[Month]
)

Months With Sales =
DISTINCTCOUNT (
    Sales[Month]
)

Sales Span Days =
DATEDIFF (
    [First Sale Date],
    [Last Sale Date],
    DAY
)

Last Calendar Date =
LASTDATE (
    Calendar[Date]
)