More than a year ago, the Ambridge Area School District sent to parents and teachers its 2006-07 calendar, noting the banner dates -- the final school day, the period for final exams, the seniors' graduation ceremony.

"People made their plans around that," Superintendent Kenneth Voss said.

	Darrell Sapp, Post-Gazette Identifying herself as "just a worker bee," a striker waves to drivers in front of the old Ambridge Area High School. Teachers walked out yesterday, canceling classes. Click photo for larger image.

But yesterday, beginning at 7 a.m., the district's teachers went on strike, rewriting those dates. They marched in front of the high school entrance, picketing and holding signs and lamenting the fruitless negotiations for a new contract. Now, because of the work stoppage, a month of plans are suddenly tenuous. The superintendent is hoping to avoid delaying the commencement ceremony; students with summer plans are scrambling to reschedule them; and, at least by yesterday afternoon, representatives from both negotiating sides were unclear about the drop-dead date by which Ambridge must complete its school year.

By state law, school must be in session for 180 days. Ambridge, so far, has completed 167 school days. When it must reach No. 180 is another question.

"June 15," said Butch Santicola, spokesman from the Pennsylvania State Education Association, which represents the teachers. "I'm certain. You have to be able to put 180 days in by June 15."

"The ultimate, end-of-the-world date -- whatever other terminal term you want to use for it -- is June 30," Mr. Voss said.

Said Mr. Santicola: "You can see why the two sides are so far apart."

Part of the confusion stemmed from a letter sent to both parties by the Pennsylvania Department of Education mentioning both dates. But June 15, state education spokesman Mike Race said, is just a target date, included in the latter as a "courtesy."

"If they blow that," he said, "it doesn't really matter. It's sometimes misinterpreted."

Ambridge, in other words, must finish its school year by June 30 to avoid losing state subsidies. Given that deadline, the more than 200 striking teachers must return to work no later than June 13, the superintendent said. Teachers have been without a contract since last summer, and bargaining within recent days has the sides no closer together, several involved said.

The teachers' union wishes for salary increases and maintained health benefits, sick days and personal days, said Mary Catherine Knafelc, union president and a 6^th-grade math teacher. The district, she said, wants to freeze salaries and reduce other benefits.

Meanwhile, the district's 2,900 students -- particularly its 232 seniors -- must wait. The May 30 Kennywood school picnic might continue as scheduled; it might, if the strike ends before then, transform into a make-up date. The commencement ceremony may continue as scheduled, even if students have not yet officially graduated, to accommodate relatives who've pegged travel plans on that date.

"There's a possibility we could have the ceremony on the [June 8] date scheduled," Mr. Voss.

The strike comes unusually late in the school year, after some soon-to-be-graduates have already scheduled senior trips to Jersey Shore or Daytona Beach, Fla. Chris Vrooman, senior and volleyball player, said he might have to change his planned orientation trip to Juniata College in Huntingdon, Pa. His volleyball team, scheduled for a second-round playoff game yesterday, lost an assistant coach because of the strike.

"He's a teacher," Mr. Vrooman said, "so this is yanking him away ... [The strike] has kind of got us all messed up."

Said Ms. Knafelc, the union president: "We've heard some parents say they really didn't want this to happen now. A few kids were going to summer sessions for college, or going to the military, or had internships lined up. We feel bad about that, because it does affect kids. But at any point when we have something like this, students will be affected."