Festivals and celebrations recognised in Auroville, often involving a holiday, are:

Auroville-related  

Dawn fire on Feb 28 (Auroville’s birthday) at the Amphitheatre. 

Other gatherings at sunrise at the Amphitheatre
February 21: Mother's birthday
August 15: Sri Aurobindo's anniversary

Darshan days at Sri Aurobindo Ashram, Pondicherry:
Feb 21, Apr 24, Aug 15 and Nov 24.

Indian/Tamil cultural

Pongal (mid Jan), Masi Magam (Feb/Mar), Tamil New Year (Apr 14), Ganesh’s birthday (Sept), Ayudha Puja (Sept/Oct) , Sangamam (February)
and Diwali (Oct/Nov).

Indian Government

Republic Day (Jan 26),
Independence Day (Aug 15),
Gandhi’s birthday (Oct 2).

International

New Year’s Day,
May Day (May 1)
and Christmas Day (Dec 25).