The Boston School Department has delayed extending the school day for more than a dozen schools that had been scheduled to add 40 minutes of learning time in the fall, officials said Friday.
The move marks a setback for one of Mayor Martin J. Walsh's signature achievements, which he touted among a list of accomplishments his administration had made in education during his annual State of the City address Tuesday.
Walsh said Friday night that he did not consider the delay a negative and that he and School Department leaders knew from the beginning that implementing a longer day would be complex.
"I wouldn't say it concerns me that we're not expanding right away to another grouping of schools," the mayor said. "Rather than create complications for parents and their children, I would rather get it right."
Parents learned of the postponement as schools across the city brace for potentially deep cuts to close a $40 million to $50 million budget deficit for the next school year.
But schools Superintendent Tommy Chang said the delay was not related to the shortfall. Chang also said the delay was not caused by problems with the rollout of an extended day in a first group of schools last fall.
"I would say that in the vast majority of cases, [expanded learning time] cohort one has been pretty successful," he said by phone. "We've gotten good feedback from principals. We've gotten good feedback from parents."
Instead, he said, the delay is a strategic decision to give officials more time to examine how the longer day affected the first group of schools to adopt it and make decisions based on what they learned.
He said School Department officials are looking at how to make a longer day work with parents' schedules and how to best stagger opening and closing times to keep transportation costs manageable.
Boston Teachers Union president Richard Stutman said in an e-mail Friday night that he believed the change was related to the deficit.
"We are disappointed that city budgetary cuts driven by a state policy that drains $121 million yearly for charter school expansion have resulted in cutbacks of essential programs such as the [expanded learning time] initiative, as well as other school budget reductions," Stutman said.
Sixteen elementary and middle schools began having a longer day last fall, and a second group of 14 was set to make the change when school begins again in September. A third group of similar size was set to extend their day in 2017.
Chang said that instead all the remaining schools that are expanding their day would do so in the fall of 2017, as required by the School Department's agreement with the Boston Teachers Union.
Chang said officials would spend the rest of this year and all of the next school year training staff and preparing for full implementation of the longer day.
The schools affected by the delay are Condon Elementary School, Holmes Elementary School, Perry K-8 School, Joseph P. Tynan Elementary School, Murphy K-8 School, Bates Elementary School, Charles Sumner Elementary School, Curley K-8 School, Horace Mann School for the Deaf and Hard of Hearing, Adams Elementary School, Dante Alighieri Montessori School, O'Donnell Elementary School, Clap Innovation School, and Clarence R. Edwards Middle School.