The calendarThe Bua Tong bloom

Tithonia diversifolia — Mexican sunflower, บัวตอง — flowers across Doi Mae U-Kho in November. It is the one thing on this circuit with a hard date.

The plant is a member of the daisy family, native to Mexico and Central America, and is naturalised widely across the tropics — in many places it is treated as an invasive weed. Here it is the reason a province runs a festival.

Inference — for a rider the consequence is a scheduling one. Khun Yuam sits on the southern leg, so which direction you ride decides whether you reach it on day two or day four — and a hillside like this wants morning light. If the bloom is the reason for the trip, pick the direction that puts Khun Yuam on a morning.

Tradition holds — the bloom is short and the exact weeks move with the year, so a date fixed months ahead is a bet.