Source: yopi.web.id/2016/08/jadwal-event-hay-day-september-2016.html
Sept 2: Riverboat Season
Sept 7: Visitors Bonus (24h)
Sept 09: Fishing Season
Sept 16: Town Visitors Coin Bonus
Sept 23: Truck Coin Bonus
Town Visitor Coin Bonus again... No XP bonus... Hmm. Not sure about these.