The Detroit school district is backing away from a new calendar for the upcoming school year after teachers pushed back against it.

The district school board approved a calendar on April 16 that moved the start of the year earlier, added teacher training days and, for the first time, closed schools for a major Muslim holiday.

But members of the Detroit Federation of Teachers voted to oppose the calendar, saying it violates their contract, and announced plans to protest the calendar at Tuesday’s board meeting. Now, the board is expect to change course during the meeting and approve a new calendar that is similar to the one that existed for the current school year.

Superintendent Nikolai Vitti said the district and union tried to negotiate in recent weeks.

“After a couple of weeks of negotiating the calendar, it is clear we cannot come to an agreement,” Vitti said. “Therefore, we need to move on to plan for professional development this summer and to provide families and staff with clarity on next year’s calendar. We have been negotiating the calendar for five months. I, the district, respect the collective bargaining agreement and that means honoring it even when you disagree with aspects of it.”

He tweeted Tuesday afternoon that returning to last year’s calendar “is less about pushback and more about an unwillingness on our part to violate the contract.”

Vitti has consistently said that leaders of the teachers union, as well as other district unions, agreed to the calendar before he took it to the board for approval. He said the dispute after the board’s sign-off would cause the district to handle calendar planning differently in the future.

“Historically, this is a verbal agreement, not a signed agreement,” Vitti said. “Moving forward, we will need to change that expectation.” That means the district will be expecting a formal agreement on future calendars, he said.

Terrence Martin, the president of the teachers union, has said he didn’t approve the calendar. He couldn’t be reached for comment about the latest development.

The union’s biggest objections were to the calendar approval process and to what leaders described as a calendar designed to prioritize standardized testing, which the union opposes. They also objected to the five additional days of professional development without a significant across-the-board pay raise. The resolution noted that district teachers are paid 20 percent less than their peers in surrounding districts.

The calendar the school board is considering Tuesday night will include the same number of required professional development days as during the current year, but it will also include some additional days that will be voluntary.

The union’s protest is also causing the district to do away with one other change that had been received warmly.

The district had earned praise from Muslim leaders for listening to students and including an observance of the Eid al-Fitr holiday next May. It included the observance of Eid al-Fitr on May 25, 2020, which would already have been a day off for Memorial Day, and the following day (a proposed professional development day for teachers). Students would have had a four-day weekend to observe the holiday that marks the end of Ramadan.