What is Puthandu?
Puthandu is the Tamil new year, the first day of Chithirai, fixed by the Sun’s entry into Mesha rather than by the Moon. Tamil Nadu dates it by sunset — if the Sun crosses into Mesha before it goes down, that day is Chithirai 1 — which is why Puthandu and Kerala’s Vishu, the same astronomical instant, do not always fall on the same day.
How it is observed
The year is met with the kanni: a tray of fruit, gold, betel, a mirror and a lamp, arranged so it is the first thing seen on waking. The new year’s panchangam is read aloud at the temple, and the meal turns on mangai-pachadi, which carries all six tastes because the year ahead will too.