English meaning of the festival
Kaarthigai refers to the month in which the festival is held. Deepam means light. Kaarthigai Deepam is a festival of lights. It is also known as Annamalai Deepam.
How the date is decided annually
Kaarthigai Deepam is observed on the day in which the combination of the full moon and Karthika star takes.
Significance of the festival to Hinduism
The lamp is considered auspicious, and it is believed to ward off evil forces. The lamp ushers in prosperity and joy. Kaarthigai Deepam is celebrated in the month of Karthigai. It is celebrated on the full moon day when the Karthika star is present. The combination of the full moon with the Karthika star is highly beneficial as it allows the light of the divine consciousness to enter into the world. This festival of lights indicates the removal of darkness or ignorance and the enhancing of light or enlightenment.
How to observe/practice
Some devotees observe a strict sathwik diet for 30 days leading up to Kaarthigai Deepam. Some devotees light a lamp on the zenith of a hill (hence Annamalai Deepam). Kaarthigai Deepam is an auspicious time to experience the light and power of God.