The calendar change will make teachers' last day June 13, which will allow for five professional days.
The School Board also voted to make some half-day and full-day adjustments to the calendar.
This Friday, March 7, originally scheduled to be a 2 1/2 hour early dismissal has been changed to a regular full day of school. Students will instead leave school early March 14, marking a new end to the current marking period.
June 5 and 6 will be full days of school and students will attend school March 28 and April 17, previously scheduled as days off, but will be excused 2 1/2 hours early, said Boyd Michael, schools executive director of secondary education.
Schools Executive Director of Elementary Education JoEtta Palkovitz-Brown said 15 minutes will be added onto both morning and afternoon kindergarten classes.
She said the extra 30 minutes will be used in elementary schools to bolster instruction in reading, language arts or mathematics.
Schools Spokeswoman Carol Mowen said altered school bus schedules were still being worked out.
The School Board decided not to touch Spring Break holidays, April 18 and 21, and Memorial Day observance on May 26, Abernethy said.
Maryland school systems are required to have 180 days of instruction during a school year, but since Washington County has already lost 12 days to inclement weather, the county school system chose to look at hours of instruction as opposed to days.
State Schools Superintendent Nancy Grasmick was given permission by the state school board to waive two school days, Feb. 18 and 19, because heavy snowfall at that time led to a state of emergency being declared in the state.
Schools Superintendent Elizabeth Morgan said the School Board must apply to receive that waiver. The School Board plans to submit an application.
The School Board voted in 1996 to add about an hour onto the school day as a result of snow days, said Michael.
He said the school system got complaints at that time about bad behavior on school buses and loss of attention in classes, but said he thinks an extra half hour won't be a problem.
"We did think the hour was way too much," he said.
Palkovitz-Brown said, "We hope the instruction will be enriching and engaging."