With storm cancellations piling up, local schools are stretching their calendars to the brink of summer to make up for lost classroom time.

Regional School Unit 71 schools were closed nine times by March 20, including two days in the fall as a result of power outages from a windstorm. Last year the district had eight snow days.

Superintendent Paul Knowles said the district's calendar doesn't build in a buffer for snow days. Barring more snow days, he said, the last day of school will be June 21. Seniors, who need five fewer classroom days, will have to return for an additional five days after their June 10 graduation.

Regional School Unit 3 has used eight snow days, but Superintendent Paul Austin said the district is in "pretty good shape" because five of those days were built into the school calendar.

To make up some snow days, Austin said three professional development days for teachers have been converted to either early release days or regular full days for students. As a result, he said, teachers will need to make up the professional development days while students are on summer break.

If the district uses more snow days, it will have to consider other options, Austin said. Adding an extra hour at the end of the day or possibly adding a Saturday school day might be considered.

The last student day is expected to be Friday, June 15, and senior graduation is slated for Sunday, June 10.

In RSU 20, students have missed 10 days of school between an October windstorm that knocked out power and a series of snowstorms this month. Business Manager Dhyana Blanchard said the two days lost in October were made up earlier in the school year and two more will be made up between March and April by completing early release days and filling in other hours when students normally would be at home.

Blanchard anticipates the six remaining days will be tacked onto the end of the term. She said the expected last student day is now June 19.

RSU 20 Superintendent Chris Downing makes the decision around graduation and how seniors will complete their required 170 days of instruction. As of March 16, seniors were one day short, Blanchard said. Downing did not immediately respond to a request for comment.

Northport students attending Edna Drinkwater School have missed eight or nine days, according to Principal Todd Martin. He said he and Superintendent Judy Harvey expect to hammer out a plan to make up some of those days but said what shape those plans might take is not yet clear. It is possible early release days on Fridays will be changed to full days, Martin said.

Two professional development days scheduled for teachers were turned into regular student days already, he said. Students at Drinkwater attended school last year until June 25, he noted, so adding extra days to the school year might be considered, although nothing is as yet set in stone.

Reporters Fran Gonzalez, Ethan Andrews and Stephanie Grinnell contributed to this report.