Karthigai Deepam is celebrated for three days. The first day is called Appa Karthigai, the second is known as Vadai Karthigai and the final day is called Thiru Karthigai. The last day is the main part of the festival and the main pooja is performed on this day.
Prior to the Pooja, the houses are cleaned and washed completely. The entrance, as well as the interior of the house, is decorated with maa kolams. The festival begins with fasting, that continues till the sunset. In the afternoon, special dishes are prepared for offering to the lord (neivedhyam). In the evening, the entire house is lighted with beautiful oil lamps. Each of the lamps has its own mythological significance. The various lamps lit during the occasion include Lakshmi Vilakku, Kuththu Vilakku, Gajalakshmi Vilakku and Aanai Vilakku.
Aanai Vilakku has a greater significance, as it rejuvenates the bond between a brother and a sister. A mythological tale tells why an Aanai Vilakku is lit during Karthigai Deepam, and what its significance is. Once there lived a king who had only one daughter, who loved an elephant that grew with her. The princess considered the elephant to be her brother. After she was married, she missed her brother a lot. Hence, in the remembrance of her brother elephant, she lit an elephant lamp and offered Milagu adai, adirasam, vella seedai and Pori urundai as neivedhyam to the lord.
