Onam is Kerala’s harvest festival and the homecoming of Mahabali, the king whose reign is remembered as the age when everyone was equal. It is dated by neither a tithi nor a sankranti but by a nakshatra — the day the Moon stands in Thiruvonam during Chingam, the first month of the Malayalam year — which is why it can fall anywhere from mid-August to mid-September.
How it is observed
The ten days run from Atham to Thiruvonam, with a pookalam — a carpet of flowers — laid at the doorway each morning, a ring wider than the day before. Thiruvonam itself is the Onasadya: two dozen or so vegetarian dishes served on a banana leaf and eaten by hand, payasam last. The vallam kali boat races and the Pulikali tiger dance belong to the same week.