With another big snowfall this week — marking Montgomery County’s 10th snow day — the question of when the school year will end has turned more complex in Maryland’s largest school district.

The last day of classes had been slated for June 12. But this winter brought nine snow days — far more than the four days the district had planned for in its calendar.

So last week, the county applied for a waiver of the state’s required 180 days of instruction.

But the waiver request did not anticipate Monday’s storm.

At the time, with nine snow days on the books, school officials took a combined approach: They could use the four snow days already built into the school calendar, ask for a state waiver of another four days and then tack one extra day onto the 2013-2014 school year.

Under this scenario, if a waiver were approved, the school year would end Friday, June 13, rather than Thursday, June 12.

The outlook got more complicated with a 10th snow day on Monday, and officials said this week they have not decided whether to amend or re-submit their waiver request to the state. Montgomery’s request is posted online.

State officials say the Maryland State Board of Education is expected to discuss the issue of waivers at its Tuesday meeting.

Extending the school year is not popular with many families. Some have made vacation plans or enrolled children in camps for what they expected to be the first week of summer vacation.

But not all parents support the idea of waiving days of instruction either. Some say that students need all of their allotted days in school. They ask why Montgomery has created contingency days for the end of the year — from June 13 to June 19 — that it now does not want to use.