The multi day celebration is observed every year in early pre-winter after the complete of the mid year gather and agrees with the new moon, known as the amāsvasya, and the darkest night of the Hindu lunisolar calendar. The good times begin two days before the night of the new moon, on Dhanteras, and grows two days after, the second day of the primary fortnight of the time of Kartik.According to Indologist, Constance  Happy Diwali GIF   Jones who has some mastery in religious human science, this night shuts the lunar month of Ashwin and starts the extended length of Kartika.The darkest night is the pinnacle of the celebration and matches with the second half of October or early November in the Gregorian calendar.

The height of Diwali is an official event in around twelve countries, while the other bubbly days are privately observed as either open or optional restricted events in India. In Nepal, it is similarly a multiday festivity, in spite of the way that the days and traditions are named in a sudden route, with the pinnacle being known as the Tihar festivity by Hindus and Swanti festivity by Buddhists.

The fundamental establishments of Diwali likely originate from a blend of gather festivities in outdated India.It is indicated in Sanskrit messages, for instance, the Padma Purana, the Skanda Purana the two of which were done in the second half of the initial thousand years AD. The diyas (lights) are said in Skanda Purana as symbolizing parts of the sun, portraying it as the galactic supplier of light and essentialness to all life and which frequently progresses in the Hindu logbook month of Kartik.One evident  Happy Diwali Messages  reference credits Diwali to the legend of Yama and Nachiketa on Kartika amavasya (Diwali night). The Nachiketa story of right versus wrong, honest to goodness wealth versus transient wealth, data versus deadness is recorded in Katha Upanishad, which was shaped in the initial thousand years BC.

Ruler Harsha implies Deepavali, in the seventh century Sanskrit play Nagananda, as Deepapratipadutsava Deepa light, pratipada  first day, utsava festivity, where lights were lit and as of late attracted women and grooms got gifts.Rajasekhara insinuated Deepavali as Dipamalika in his ninth century Kavyamimamsa, wherein he indicates the custom of homes being whitewashed and oil lights lit up homes, lanes and markets in the night.

Diwali was also depicted by different pioneers from outside India. In his eleventh century diary on India, the Persian voyager and understudy of history Al Biruni made out of Deepavali being applauded by Hindus upon the entry of the New Moon in the time of Kartika.The Venetian dealer and pioneer Niccolò de' Conti visited India in the mid fifteenth century and wrote in his journal, "on another of these festivals they repair inside their havens, and apparently of the housetops, a perpetual number of oil lights... which are kept devouring day and night" and that the families would amass, "dress themselves in new bits of apparel", sing, move and feast.