Deepavali (as it is known in Sanskrit and in Tamil) or Diwali (as it is more widely known), is celebrated over 5 days in India. This year the first day of Deepavali starts on the 24th of Oct and the start date coincides with the darkest night (i.e. on the day of the new moon) of the Hindu month Kartik.
In Malaysia, where I hail from, Deepavali is celebrated on the 24th and it is a National public holiday. Stories are many in how it came to be depending on which region one heralds from, but the day symbolizes the victory of good over evil or light over darkness and Hindus mark this occasion with the lighting rows of oil lamps. Deepa means light and vali means row, so the word Deepavali literally means a row of lights.
Our family start the festivities on the day by taking a ritual oil bath, performing a Pooja (prayers), adorning ourselves with new clothes, paying a visit to the temple, treating ourselves to a sumptuous meal and yes, lighting a row of oil lamps as the sun sets in the horizon.
Over in Malaysia, we used to practice this concept of "open homes" during major festivities, where friends and family, even non-adherents, are openly welcomed at the homes of those celebrating the religious festival. Basically Malaysians used to have open homes for Christmas, Eid, Chinese New Year and Deepavali.
Of course what festival is complete without gifting, non-stop eating, traditional sweets and desserts along with some fireworks to finish off the day? Deepavali is no different when it comes to all this.