The cuts will begin Saturday, Gallard said.
The changes mean that all weekday extracurricular activities and programs - including Recreation Department activities, school programs, and athletic events - will now end by 7:30 p.m. so buildings can close by 8 p.m.
Organizations that pay the district to use its buildings will still be able to use them. It is unclear if these groups will be able to pay to keep the buildings open longer.
In a letter Friday to elected officials, a district official wrote: "These organizations will be billed for the cost of keeping the school open for their activities. Organizations that currently have payment agreements with the district will be grandfathered into those agreements, but all new activities will be paid for according to the district's payment schedule."
The changes "are being enacted to create a substantial savings in utilities, personnel and overtime spending," the letter said.
The decision to shut buildings early was "difficult," the district wrote in its letter.
On Friday, the district eliminated 91 school police jobs, eight regional office jobs, and six central-office jobs. The police cuts save $617,000; the district did not release total savings of the other cuts.
Also unclear is how much the district must cut before June.
The school police cuts mean that 100 schools are now without permanent officers stationed in their buildings, up from 75 schools.
The cuts come on top of thousands of layoffs and deep program cuts in September and December and more reductions announced in January, including a drastic cutback in summer school, and pay-raise recisions, furloughs, and salary reductions for some nonunionized administrative employees.
Officials have said cuts to school psychologists were also on the table, as were elimination of spring athletics, instrumental music, gifted programs, and bilingual counselors. Those decisions have not yet been made, however.
City Controller Alan Butkovitz, who has questioned the district's financial viability, has estimated the district will need to cut $400,000 a day to make up the $61 million shortfall by June.
The district already faces a $269 million budget gap for its 2012-13 fiscal year.
Contact staff writer Kristen Graham at 215-854-5146, firstname.lastname@example.org, or @newskag on Twitter. Read her blog, "Philly School Files," at www.philly.com/schoolfiles