The School Committee approved extending the day at more than 50 schools by 40 minutes Wednesday night, even as it prepares to slash spending in the coming weeks.
The $12.5 million plan passed by 5-to-1 vote, and came two weeks after the Boston Teachers Union membership overwhelmingly ratified the deal.
School and union officials hope the extra time will boost the academic performance of students so the school system can avoid any state sanctions for low achievement. Dozens of Boston schools rank in the bottom 20 percent in MCAS scores statewide. That puts them at risk of being designated underperforming by the state, a move that can lead to wholesale changes in staffing and administration.
John McDonough, interim superintendent, urged committee members to pass the proposal before the vote. The school day changes will affect more than 23,000 elementary and middle school students, but the city’s public high schools will not be included.
“This is in the best interest of students,” said McDonough.
School Board member Meg Campbell cast the dissenting vote, citing concerns about funding a new initiative as the school system grapples with a potential shortfall of $90 million next school year.
“I’m not happy about this vote,” said Campbell, who runs the Codman Academy Charter School, which has an extended day and operates independently of the school system.
The School Committee vote was the final step in the approval process. The extended time will be phased in over the next three years. The school system expects to name in the coming days the first group of approximately 20 schools that will lengthen their day.
Currently, most elementary schools are in session for six hours a day and middle schools for six hours and 10 minutes per day.
“This is a historic moment in public education for Boston, and I am pleased this agreement is moving forward,” said Mayor Martin J. Walsh, in a statement. “Boston’s students deserve more learning opportunities. The extra 40 minutes will mean more time for academic learning, more time for enrichment opportunities, and more time for added supports for struggling students.”
The school system has been pushing for an extended day for years, but often clashed with the teachers union over additional pay and how much say teachers would have in how the extra time is used.
Under the deal, announced the day after Christmas, teachers will have a voice in developing the extended day for their school and their annual salary will increase by $4,464.
The extra time will be used to provide additional instruction in math and English and expand opportunities for art, music, science, and other enrichment activities. Teachers will also have more time to plan lessons together and identify ways to help students struggling academically.
In public testimony before the vote, a financial watchdog and a parent raised concerns about the plan.
Samuel Tyler, president of the Boston Municipal Research Bureau, a watchdog funded by businesses and nonprofits, said his organization supports a longer day but questioned the price tag in light of the anticipated budget shortfall.
“Is $12.5 million for 40 minutes a prudent deal?” Tyler asked.
Kristin Johnson, whose daughter attends Mendell Elementary School in Roxbury, said her school was prepared to file a plan to extend its day in the first round, but decided against it primarily because of scheduling problems.
The school starts classes at 9:30 a.m., and adding 40 minutes would push dismissal to 4:10 p.m., taking time away from sports and afterschool programs and creating problems for students going home.
“The BPS buses bringing our children home are already routinely 30 minutes late,” Johnson said. “If this track record continues, this puts kids into rush hour traffic, wasting time sitting on a bus, when they could be doing homework, playing sports, or spending time with family.”
She asked the committee to let more schools start their days earlier.
McDonough said the school system is still working out late dismissal issues with schools that begin days at 9:30. Ideally, he said all schools would start at 8:30, but the school system needs to stagger the opening of its schools in three waves so buses can do more than one route, keeping costs down.
Michael O’Neill, the School Committee chairman, urged school district administrators to work swiftly in finding new start times so no school has to dismiss too late.James Vaznis can be reached at email@example.com. Follow him on Twitter @globevaznis.