Today (November 13, 2012) marks the first day of a major five-day religious festival — in fact, the largest and single most important holiday on the Hindu religious calendar.

Observed in India and beyond not only by Hindus but also by Jains, Sikhs, and even some Buddhists, Diwali (“festival of lights”) is characteristically celebrated by the lighting of numerous oil lamps, candles, lanterns, bonfires, and other forms of illumination. These ubiquitous glowing lights symbolize the inner luminosity of the soul and the blissful illumination of spiritual awakening or “enlightenment,” as well as the glory of the ultimate triumph of good over evil.

During Diwali, homes are cleaned, new clothes donned, families gathered, treats shared and fireworks ignited, all expressing the joy of new beginnings. An official holiday throughout much of the Hindu cultural world in south Asia and elsewhere, Diwali traditionally signals the end of the harvest season and the beginning of a new agricultural year; it also marks the start of a new fiscal year for businesses. For some regional ethnic groups in India, Diwali is in fact their New Year’s Day.

Although perhaps best known as a major Hindu holiday, with its various celebratory events linked to specific Hindu deities, themes, and traditional tales, Diwali is likewise observed in other faiths that also had their origins in India.

For Jains, Diwali commemorates the occasion upon which Jainism’s founder Mahavira (599-527 BC) attained kevala (perfect and infinite spiritual omniscience) and moksha (release of his soul from the otherwise endless chain of birth, death, and rebirth).

For Sikhs, Diwali closely coincides with the Sikh holiday Bandi Chhor Divas (“Day of Liberation”), the historic release from imprisonment of Guru Hargobind Singh (1595-1644 AD), the sixth of Sikhism’s ten holy gurus.

And for some South Asian Buddhists, Diwali is a minor holiday commemorating the conversion to Buddhism of India’s emperor Ashoka (304-232 BC), an important ruler honored as an influential royal supporter, promoter, and patron of early Buddhism.

To celebrants worldwide of this significant religious holiday (the biggest holiday on the Hindu calendar), may I wish you all the traditional Hindi greeting of “Diwali ki Shubhkamnayein!” — or, as expressed in English, “Happy Diwali!”