But if the teachers stay out until June 15, they won't have enough time to complete their contracted 188.5 days, School Board President Ritchie Webb said.
"Some will lose as much as four to five days' pay, others more," Webb said. "It varies depending on the position."
Members of the NFT, which represents 633 teachers, guidance counselors, librarians and nurses, "went into this knowing some wages were in jeopardy," union vice president Anne Schmidt said.
They could lose three to five days' pay, she said.
The union has been working under an expired contract for nearly four years, in what is the longest current impasse in the state. Members have not gotten a raise since 2008, but have received benefits that the board says it can no longer afford, such as health care without contributions and a $27,500 retirement incentive with full insurance coverage.
Meanwhile, the district pulled its offer, including 1 percent raises this year and the next two years, off the table Tuesday, as it has done each spring since 2009, Sweet said.
"After 4½ years of bargaining, the board could get tougher, but that won't get a settlement," he said.
Pulling the offer "gives the board the opportunity to work out something else," Webb said. "The economy is not getting any better."
Each year, the board repeats its position that it cannot pay retroactive raises for time worked and education credits earned, Webb said. The union's call for 80 percent retroactive pay would cost the district about $14 million this year, he said.
"I don't know what to make of it," Schmidt said of the district's move.
The union's proposal also includes annual wage increases of 1.00 percent to 3.25 percent from last year through the 2013-14 school year, and a reduction in the retirement incentive. The teachers have offered to pay 8 percent of the first-year health insurance premiums each year, compared with the district's proposed 15 percent per year.
Both sides were notified of the June 15 deadline Tuesday by the state Department of Education. Kindergarten teachers must return by June 14, Schmidt said.
The union's lawyers were reviewing the department's directive, she said.
The department is preparing to seek an injunction in Bucks County Court to ensure that classes resume by June 15, Sweet said, even if the union agrees to return.
Contact Bill Reed at 215-801-2964 or email@example.com, or follow on Twitter @breedbucks. Read his blog, "BucksInq," at www.philly.com/bucksinq.