For the world's 1.1 billion Hindus, the autumn holiday of Diwali is like Christmas, New Year's Day, and the Fourth of July wrapped into one – a time to gather with family, exchange gifts, illumine homes with candles and colored lights, attend temple services, and shoot off firecrackers deep into the night.

Yet for thousands of Indian American children and their parents in the Philadelphia region, the ancient festival of lights  is just another school day, its revelry muffled under a mound of math homework.

"For a lot of people like myself, [Diwali is] a cultural activity, just as Christmas," said Dell Joshi, a DuPont engineer whose two children are among a growing number of students of Indian heritage in the Unionville-Chadds Ford public schools.

When Diwali comes this year on Oct. 19, however, everyone in the district will know it. Earlier this year, Unionville-Chadds Ford voted to make official school holidays of both Diwali and Lunar New Year, which in 2018 will fall on Feb. 16. The roughly 4,000-student district, which straddles the border of Delaware and Chester Counties, appears to be the first in Pennsylvania to formally mark either Asian holiday, although the trend already is underway elsewhere.

Unionville-Chadds Ford's Asian population more than doubled between 2000 and 2010, according to census data, and currently comprises 10 percent of the student body. In addition to Hindus, many Sikhs, Jains, and some Buddhists observe Diwali, or Deepawali, which dates back at least two millennia and celebrates the victory of light over darkness, knowledge over ignorance, good over evil.

"We're a diverse community and we wanted to be respectful and really accepting of all the different cultures that make up our community," Superintendent John Sanville said.

In Unionville-Chadds Ford, the median household income in 2015 was $117,300 -- 1½ times greater than other Chester County communities and double the rest of the state.  Likewise, many of the East Coast districts that give students the day off for Diwali or Lunar New Year, or both, tend toward the upscale, and include such central New Jersey school systems as West Windsor-Plainsboro, Piscataway, and Glen Rock.

But where Unionville-Chadds Ford and others have forged ahead, an increasing number of school districts around the country are grappling with how to handle a slate of holy days outside the Judeo-Christian tradition – not only Diwali and Lunar New Year, celebrated by Chinese, Koreans, and other Asians, but also the Muslim celebrations of Eid al-Fitr and Eid al-Adha.

"It can get tricky," said Suhag Shukla, of Haverford, executive director of the national Hindu American Foundation.

She noted that some districts end up being forced to choose between Muslim and Hindu holidays, risking a backlash from the community left out. Nonetheless, Shukla said she's encouraged by the recent spike in districts that at least make note of Diwali, and allow excused absences. "Building it in the calendar is great," she said, "so that it's on the radar for teachers and it gives students a feeling that 'my school and teachers know about me.' "

In 2016, the Philadelphia School District added the two Muslim holidays to its calendar, with encouragement from Mayor Kenney and other public officials. It won't be until next year, however, that either falls on what would have been a regular school day.

John Chin, executive director of the Philadelphia Chinatown Development Corp. and chair of the Mayor's Commission for Asian American Affairs, said he would love to see city schools make a holiday around Lunar New Year. He compared schools' recognition of diverse religions to the movement to tear down Confederate monuments in the South.

Lunar New Year is observed in New York and San Francisco schools, as well as a few smaller districts, such as Long Island's Great Neck. Howard County, Md., recently voted to honor Lunar New Year, Diwali, and the two Muslim holy days, in addition to retaining two Jewish holidays.

A 2014 Pew Research Center study found that among Pennsylvania residents, 1 percent were Hindu and Muslim and less than 1 percent Buddhist. However, census data showed the Asian population – especially Indians – rising rapidly in the Philadelphia suburbs. The highest growth rate was in Chester County, which gained 5,631 new residents of Indian heritage during the 2000s, a 198 percent increase.

Some Philadelphia-area districts say they're looking more closely at their policies toward Diwali as their enrollment of students with South Asian roots expands. Bensalem in Lower Bucks County, where roughly one in seven students is Asian, does not close, but religious holidays can be claimed as an excused absence with a note.

Ankit Parikh, one of two Indian American school board members in Bensalem, said making Diwali an official school holiday has never come up in the district, but it would be a good idea. "It would benefit students in general to open their knowledge and understanding of other people and their descendants from other countries," he said. "I think it would be a step in the right direction."

That same spirit motivated officials in Unionville-Chadds Ford. Superintendent Sanville said observing Diwali and Lunar New Year bolsters his belief that exposure to cultural diversity makes graduates more successful later in life.

But the vote there came not long after a controversy over the treatment of Asians and other nonwhite students in the district. A school board member, Michael Rock, resigned in early January with a public diatribe accusing the district of taking a lackadaisical approach to reports that minority students were bullied after President Trump's election.

Rock said district officials and board members had been ignoring his pleas for action on bullying, including an incident in which a rock bearing a Hillary Clinton sticker reportedly was thrown through the window of a Muslim student's car. The vote to observe Diwali and the Lunar New Year was a response to the controversy, he posited. "It's their attempt to mollify the Indian community."

According to others in the district, though, the conversation about making Diwali a holiday had been going on as long as three years. The district's only motive, Unionville-Chadds Ford board member Bob Sage said, was "to recognize in our community that we have a diverse group of kids and families, and we should not be recognizing religious holidays only from two religions, just as a matter of principle."