Avinash Gupta fondly remembers the Diwali celebrations of his youth in India, which were filled with sweets, colourful diyas (oil lamps) and firecrackers.

Since arriving in the United States in 1986, Gupta, a physician, has developed traditions that make celebrating Diwali in his adopted home country just as special. During the five-day celebration, Gupta stops by his New Jersey medical practice at night and turns on all the lights so guests arrive the next morning to an office brightened in the spirit of the festival of lights.

“We decorate the physicians’ lounge, and American friends,” Hindu and non-Hindu, “come and enjoy the sweets,” Gupta says. Recalling Diwali celebrations past and present, Gupta says he especially looked forward to the sweets and fireworks when he was growing up. But his appreciation of Diwali has shifted over time.

“Now, the best part is the sense of togetherness,” he says. Diwali, one of India’s most significant religious and cultural holidays, is “a time to reconnect with family and friends, and to engage in prayers for prosperity and well-being.”

Observed by Hindus, as well as Sikhs, Jains and some Buddhists, Diwali marks the triumph of light over darkness, knowledge over ignorance and good over evil. It’s celebrated across South Asia and in countries with large South Asian diasporas like the United States, Australia, Canada, the United Arab Emirates and the United Kingdom.

The holiday falls in late October or early November, though the specific dates vary based on the Hindu lunar calendar. One billion people celebrate worldwide, including millions in the United States.

During Diwali, Gupta says, family and friends exchange gifts and sweets, while homes, temples and businesses are decorated with diyas and fireworks light up the sky. Gupta and another immigrant from India, Vandana Kumar, of Morganville, New Jersey, say U.S. Diwali celebrations involve many of the same traditions as those in India.

Families clean their homes to prepare for guests and break out their traditional garb: colourful saris for women and flowing kurta for men. On Diwali’s first day, also known as Dhanteras, celebrants purchase gold and silver jewellery or utensils for prosperity.

While diyas left outside homes are intended to attract Lakshmi, a goddess who confers wealth and prosperity wherever she encounters light, Gupta says the holiday also celebrates “spiritual growth and [the importance] of community, charity and gratitude.” “People go out and give blankets and food to the homeless,” he adds.

“Whatever we have, we are grateful for.” Kumar, who moved to the United States in 2012, enjoys preparing for Diwali with her two sons.

They make the traditional Indian sweet laddu from flour, sugar and butter. Other treats commonly served during Diwali are barfi, similar to fudge, and crispy fried, syrup-soaked flour spirals called jalebi.

The family also prepares “a balance of different foods,” Kumar says, which might include savoury snacks like vegetable samosas and grilled paneer wraps served before a main dish of curry. “Diwali is as prominent in Indian culture as Christmas is in most Western societies,” Kumar said.

Family and friends, Hindu and non-Hindu, visit each other’s homes to enjoy a familiar holiday or learn about a different culture. “It’s about inviting positivity inside your house, while banishing darkness and negativity.”