In recent years, school leaders in Maryland have had little choice about when they would hold the first day of classes. It had to be after Labor Day, in keeping with an executive order issued by Gov. Larry Hogan (R) in 2016.

But a new state law has upended the Hogan order, returning decision-making power to local officials. So as school systems draw up academic calendars for 2020-2021, the idea of opening in August is back — with some systems considering start dates a week before Labor Day, even two weeks.

“It gives us a lot more flexibility,” said Patricia O’Neill (District 3), a school board member in Montgomery County. “We’ve always argued from day one that the calendar should be under local control.”

Montgomery’s board decided this week to open on Aug. 31 in 2020 — as did Queen Anne’s County on the Eastern Shore. Howard County went earlier still, voting for a calendar with a first day of classes Aug. 25.

All are well ahead of Labor Day, which comes later than usual in 2020 — Sept. 7.

“There are so many good reasons why starting early makes sense,” said Brad W. Young, president of the Frederick County Board of Education.

Young said getting more learning in ahead of Advanced Placement testing dates in May is important. “Starting late puts our kids at an educational disadvantage,” he said.

And, he added, students tune out as the academic year winds down.

“Days in June are not as valuable as days in August or September,” Young said.

In Prince George’s County, two calendar options go to the school board Dec. 12, with both showing school’s start as Aug. 31. A survey is planned next, with a board vote expected in January.

The year Hogan’s mandate was announced, all but one of Maryland’s 24 school systems opened before Labor Day.

Hogan said his summer-extending decree would boost businesses, give families extra vacation time and save on school air-conditioning costs, and he cited polls showing strong support for a post-Labor Day start.

Michael Ricci, a spokesman for the governor, noted the wide support for Hogan’s post-Labor Day schedule — and he predicted turmoil to come.

“Partisan legislators and special interest groups have now created mass confusion where different districts will go back to school on different dates,” he said in an email. “We expect that legislators will have a lot of explaining to do after this confusion sets in for families across the state.”

From the beginning, many school systems complained about the edict, saying the compressed time frame — starting after Labor Day and ending by June 15 — put a squeeze on spring breaks, teacher professional days and other time off during the school year.

They also expressed concerns about learning losses that disadvantaged children in particular could face with a longer summer; some said more time in school was needed, not less.

But three years later, some school systems, including Baltimore County, have kept to the post-Labor Day approach that Hogan advanced. During a school board discussion, one member highlighted a lack of air-conditioning at six county schools, and another member pointed to the value of student participation at the state fair, a spokesman from Baltimore County said.

In Anne Arundel County, the school board voted 6 to 3 to open Sept. 8, with board member Melissa Ellis (District 4) arguing that a post-Labor Day date was best for learning.

“A long summer is more beneficial to students than students being out of school for 10 days for spring break, because then we create a greater impact in the middle of the school year to learning,” she said.

In Anne Arundel, 51 percent of those who answered a board survey favored a calendar option starting after Labor Day, while 49 percent wanted a pre-Labor Day start.

Those who argue for local control say that each school system has its own priorities and that calendars typically emerge from local committees that include educators, staff members, parents, students and community leaders.

In agriculture-minded Frederick County, Young pointed to the long tradition of closing schools on a Friday in September for Fair Day, so that students get the chance to attend the county fair.

In Montgomery County, students have been off school on Muslim holidays in recent years, with school officials placing a professional day on those dates. Schools in Montgomery have closed for the Jewish holidays of Yom Kippur and Rosh Hashanah since the 1970s. Under state law, schools close for Christmas, Good Friday and the Monday after Easter.

When Montgomery did a survey of calendar preferences for the 2020-2021 school year, more than 10,300 people favored starting before Labor Day — on Aug. 31 or Sept. 1 — while slightly more than 2,000 urged a post-Labor Day start on Sept. 8.

O’Neill said a full spring break has emerged as important in the state’s largest school system. Montgomery cut back on spring break last year — not a popular move.

“Our community cherishes spring break, and we’ve heard that loud and clear,” O’Neill said.

State Sen. Paul G. Pinsky (D-Prince George’s), who sponsored the Senate bill that overturned Hogan’s order, said momentum for the change had been building in the years since the Hogan order was issued — and the 2020-2021 calendar was going to be an especially difficult task for local leaders, with Labor Day coming so late.

The legislation passed the General Assembly and was vetoed by Hogan, but lawmakers overrode the veto.

Pinsky argued that Hogan’s order was largely about boosting business in tourism-minded Ocean City and extending the labor pool of high school students who could work through Labor Day.

The change will not provoke turmoil, he predicted. “For 50 years, maybe longer, the local boards set their calendars and there was never chaos,” he said. “Each county has a better sense of what is best for their community.”