ALBANY—State lawmakers, facing an angry electorate this fall, are flexing their muscles to hold up adoption of the state budget in order to find more money for public schools.

But the clock has ticked away enough so that any cash they do uncover beneath the mattress will not be able to undo planned layoffs and cuts to student programs proposed in many districts.

That’s because a deadline quietly slipped by Saturday, unnoticed by many lawmakers, which was when the state’s 700 school districts had to submit their budget plans for the upcoming year to the state Education Department.

Without some extraordinary action from Albany — like changing the upcoming May 18 vote by residents for public school budgets, which is suddenly being discussed at the Capitol — any extra money found for schools could be used only to lower property tax levies or for reserve funds.

“The budget has already been adopted, so it cannot impact the expenditure side at all,” Terry Ann Carbone, superintendent of the Lockport City School District, said of the possibility of more-than-expected state aid going to districts. “The board cannot spend one penny more than when they adopted the budget.”

Over the years, districts got well-accustomed to dealing with late state budgets. The budget was due by March 31. And in flush years, late budgets were generally no big deal because districts could generally be certain that any school aid number proposed by a governor was certain to be added to by the Legislature.

But this year is different. Gov. David A. Paterson proposed, with the backing of Senate Democrats, a budget that would cut school funding by $1.4 billion. For instance, in Lockport, which relies on the state for nearly 60 percent of its funding, it would mean a nearly 10 percent cut.

But Assembly Democrats adopted their own budget plan last month, adding back to the schools $600 million over the Paterson level.

It has been a stalemate ever since. In the meantime, schools have had to craft their own 2010-11 budgets, and most, to be safe given the state’s soaring deficit, devised budgets using the lower Paterson school aid number.

“The lateness is harder this year because the choices are worse,” said Robert N. Lowry Jr., deputy director of the New York State Council of Superintendents.

Silver, and even some Senate Democrats, have said that adding more money to schools is a priority. But if the idea is to help local schools turn back plans to lay off teachers, cut sports programs and reduce spending further, the clock has run out for many districts.

To get fiscal details — known as property tax report cards — to the Education Department by last Saturday, school boards across the state had to have previously passed their 2010-11 budgets, which they did over the last few weeks. Those plans then go before voters May 18 — except in Buffalo and four of the other big cities in New York.

Now there is talk in Albany of delaying that vote with the hope — as in 2003 — that the warring sides at the Capitol could reduce Paterson’s school aid reduction numbers. If the date were changed, and if more state money went to schools, the theory is that districts could then amend their proposed budgets and alleviate some of the spending cuts to take into account the new support from Albany.

But districts already have spent millions of dollars statewide preparing for that May vote in the form of mailings and advertising and other means to notify voters of their budget plans.

“It’s not clear that districts could amend their property tax report card if the Legislature were to pass the budget in the next week or so,” Lowry said.

Such a timetable would be extraordinarily optimistic. Talks are stalled at the Capitol, as the sides await each other to blink on various fiscal matters.

Timothy G. Kremer, executive director of the New York State School Boards Association, said it is a “legitimate interpretation” that it is too late for schools to undo proposed spending cuts even if Albany comes through with more money.

“Once the district submits property tax report cards to the state Education Department, everything after that is revenue-neutral,” Kremer said.

Still, schools are not saying no to extra funding. “A bunch of my members would say if we could hang out there and hope for additional federal or state funding, it’s worth it,” Kremer said. But he said that many schools would not want to delay the May 18 vote.

“If we get additional state aid, the only way to be able to take advantage of that for programs is if the Legislature gives us the authority to do so,” Kremer said, “Otherwise, it’s for property tax relief or reserves.”