CHARLESTON — Gov. Joe Manchin’s school calendar bill sailed through the Legislature this month with such strong support that only a single lawmaker voted against it.

That near-unanimity may not last.

County school boards reviewing the proposal, which permits them to set the start and end dates of the school year, worry it won’t give them enough flexibility to ensure students get 180 days of instruction time.

But unions representing teachers and other school employees, which helped scrap a similar bid to change the calendar last year, say they don’t see a need to revisit the issue now that the bill is awaiting Manchin’s signature.

“We just passed a calendar bill that gives counties flexibility, and I hope we would give them the opportunity to make this work,” said Dale Lee, president of the West Virginia Education Association.

The unions and lawmakers report hearing that another bill addressing the calendar will be introduced soon, but Manchin spokesman Matt Turner said there’s nothing to that talk, at least for now.

“We’re elated with the bill passing,” Turner said, “but if something needs to be looked at in the future, that’s something we might do.”

State policy already calls for 180 days for students, but counties routinely struggle to comply. Winter weather can close schools, and counties also reserve days for training, meetings and other non-class reasons.

The problem, some county school boards and superintendents say, is that the new bill doesn’t allow enough flexibility to ensure 180 days of classroom time.

The legislation strikes the current state mandate fixing the first and last days of school, but some school employees must work a contractually mandated 200 days within a given time frame.

Counties are therefore still limited in how early school can begin and how late it can end, said Richard Olcott, president of the West Virginia School Board Association.

“What I’ve heard from folks is the bill does provide some flexibility but it’s just a few days,” said Olcott, who is also vice president of the Wood County school board.

“It probably addresses the problem in counties that don’t have as much inclement weather, but for other counties, we’re still not there yet in terms of flexibility,” he said.

It’s not clear, though, that the Legislature is keen on reopening a debate that last year highlighted divisions between the House of Delegates and state Senate and resulted in one of Manchin’s top agenda items failing at the last minute.

“I haven’t heard any specifics except that it’s out there,” said House Education Chairwoman Mary Poling, D-Barbour, referring to a second calendar bill. “I’ve just heard the general statement, not necessarily from the governor, but that there’s interest in a follow-up.”

The ease with which the measure passed the Legislature this year caught many by surprise. Last year, while the Senate endorsed a version similar to the current bill, the House changed it so that instructional time was counted by the minutes spent in class, rather than by number of days.

This time, the bill Manchin wanted was the bill he got.

“We were pretty surprised with that,” Olcott said. “We don’t know why it moved so fast this year.”