[JoelJacobson]

Good example too, but this one can with benefit be written using the JOIN FOREIGN syntax, you just need to give the foreign keys suitable names such as e.g. "shipped_date", "order_date", "received_date". Or, to remind you of which is the referenced table, perhaps you want to include it in the names, and the names would be "shipped_date_calendar", "order_date_calendar", "received_date_calendar", but personally I would prefer just "shipped_date" or perhaps even just "shipped".