The bonfire the night before Holi is lit on the full moon of Phalguna, and the colour-throwing happens the following morning.

The fire commemorates Holika, who burned instead of the child she was meant to burn, and the day after is the licensed disorder — the one day of the year when the usual rules about who may throw what at whom are suspended. Two consecutive days, one lunar, one social, and the moon sets the date for both.