I do not if this is already an event or not but here it goes.
Market Day would be a day where all towns come to sell their products to other players/towns for money, The market would be once a week (sunday) and would be on all day since 10am to 1am.
--Leaflet--
Market day!
Time: Sunday from 10 am to 1 am!
Place: TBD (could be different towns every week)
Items Sold: All kinds from anything from dirt to diamond!
--Leaflet--
That would be a sample leaflet but it could be different.
Thank you for your time.