...I live in Silicon Valley CA, which has a very large Indian population.
A few years ago I saw a multitude of Christmas lights on homes and apartments well outside of the Christmas season. I thought "huh?"
So then I learned about Diwali:
http://en.wikipedia.org/wiki/Diwali Diwali, or Deepawali, (also called Tihar and Swanti in Nepal) (Markiscarali) is a major Indian and Nepalese festive holiday, and a significant festival in Hinduism and some of the other faiths which originated in India - Jainism and Sikhism. It originated as a harvest festival, marking the last harvest of the year before winter. In an agrarian society this results in businessmen closing accounts, and beginning a new accounting year. The deity of wealth in Hinduism, Goddess Lakshmi is therefore thanked on this day and everyone prays for a good year ahead. This is the common factor in Diwali celebrations all over the Indian subcontinent. With time, many legends became associated with Diwali, and today it is celebrated by Hindus, Jains and Sikhs across the globe as the "Festival of Light," where the lights or lamps signify victory of good over the evil within every human being. The festival is also celebrated by Buddhists of Nepal, particularly the Newar Buddhists.
The Sanskrit word Deepavali means an array of lights that stands for victory of brightness over darkness. As the knowledge of Sanskrit diminished, the name was popularly modified to Diwali, especially in northern India. The word "Divali/Diwali" is a corruption of the Sanskrit word "Deepavali" (also transliterated as "Dipavali"). Deepa/dipa means "light of the dharma", and avali means "a continuous line". The more literal translation is "rows of clay lamps".
Of the many legends, the most popular association in Northern India is the homecoming of King Rama of Ayodhya after a 14-year exile in the forest. The people of Ayodhya (the capital of his kingdom) welcomed Rama by lighting rows (avali) of lamps (deepa), thus its name, Deepawali, or simply shortened as Diwali.
Southern India marks it as the day Lord Krishna defeated the demon Narakasura. In western India it is also in honor of the day King Bali went to rule the nether-world by the order of Vishnu. (There is another festival 'Onam' which is celebrated in Kerala around the month of August to mark this legend)
In Jainism it marks the nirvana of Lord Mahavira, which occurred on Oct. 15, 527 B.C.
The Sikhs have always celebrated Diwali, however its significance increased historically when on this day the Sixth Guru, Guru Hargobind Ji, was freed from imprisonment along with 52 Hindu Kings (political prisoners) whom he had arranged to be released as well. These prisoners were all released at the same time from the famous fort of Gwalior by Emperor Jahangir in October, 1619. Since the kings were also freed, Guru Ji became known popularly as the "Bandi Chhorh" (deliverer from prison). He arrived at Amritsar on Diwali, and the HarMandar Sahib (the "Golden Temple") was lit with hundreds of lamps in celebration. For Sikhs, this day was thereafter known as the "Bandi Chhorh Divas" (the day of freedom).
In India, Diwali is now considered to be a national festival, and the aesthetic aspect of the festival is enjoyed by most Indians regardless of faith.
Also called Translation: Row of Lights; Deepavali, Festival of Lights
Observed by Religiously by Hindus, Sikhs and Jains. Other Indians celebrate the cultural aspects.
Type Religious, Indian
Significance Celebrate victory over evil, and uplifting of spiritual darkness/
Date New moon day of Kartika, although the celebrations begin two days prior and end two days after that date
2006 date October 21
2007 date November 9
2008 date October 30
Celebrations Decorating homes with lights, Fireworks, distributing sweets and gifts.
Observances Prayers, Religious rituals (see puja, prasad)