On Monday -- which in past years would have been the first day of school in Loudoun County -- Meg Upp took her three children to the playground instead.

To celebrate their final week of freedom, she gave her three youngsters their choice of daily activities. Six-year-old Alex declared that her day should be devoted to buying a puppy -- or a trip to the playground. Hence, Ida Lee Park made the list.

The Upp crew of Leesburg was enjoying having extra time together, Meg Upp said, but the additional vacation has been wearing at times. "We have had mixed emotions about this," she said.

For the first time in recent memory, Loudoun schools start the day after Labor Day rather than the last week in August. When school begins at last on Tuesday, a projected total of 44,715 students will flood the county's classrooms -- 3,964 more than last year. The fast-growing county has hired 655 teachers and will open three new schools to keep pace.

With the later school start -- and the fact that Labor Day is Sept. 6 this year, about as late as it ever falls -- parents and students were especially aware of the extended vacation.

For the Lockwood family of Purcellville, it meant an opportunity for a vacation to Ocean City, N.J. Michele Lockwood said that she wanted to take a last beach vacation in past years but that the early start of school prevented it. "We wouldn't have taken him out of school to go," she said, referring to her 12-year-old son, Kyle.

Kyle agreed that the extra week has been good. "It's given us more vacation," he said, which for a kid, of course, is never a bad thing.

Virginia law requires schools to start after Labor Day, but districts with a history of days lost because of snow can obtain a waiver and start earlier. Loudoun has qualified for the waiver in past years but did not this year based on weather cancellations over the last decade.

The measure is known informally as the "King's Dominion Law" because lobbyists for the amusement park oppose efforts to overturn it, arguing that business would suffer if Virginia children were in school during the busy week leading up to the three-day weekend. Locally, only Fauquier County schools qualified for a waiver, and those students started back to school this week. In Maryland, however, many schools started this week, and some started last week.

Loudoun Superintendent Edgar B. Hatrick III, who has long supported starting school earlier, said the law inappropriately ties the hands of local administrators.

"The notion that an elected school board can't decide when to start school is silly, and it has nothing to do with education," he said.

To ensure graduation dates are not pushed back, the school calendar has been shortened from 185 to 183 days this year, and students will have to attend on Columbus Day.

Hatrick said it was "technically possible" that Loudoun would qualify for the waiver next year and return to its more familiar schedule. But he said the School Board would have to examine the options carefully. "I don't think we can yo-yo families back and forth," he said.

The extra time put some parents in a bind. Kim McDevitt of Ashburn said her children's summer camp schedules were designed around the old calendar and ended Aug. 15.

As a result, she found herself without child care for the last three weeks of summer.

"It put us in a real pickle," she said. Ultimately, McDevitt took time off from work, and the family went camping.

Teachers, who have been attending staff development events since Aug. 25, were split about the late start. Sheri Shackelford, a third-grade teacher at Lincoln Elementary School, said that she appreciated the extra planning time and that students would be better prepared to learn after Labor Day and the psychological start of fall.

"When we started earlier, they felt like summer wasn't over yet," she said.

Becky Sands, a third-grade teacher at Cool Spring Elementary School in Leesburg, argued that starting before Labor Day gives students time to ease into routines. "You use that week to get them all settled, and then you start Tuesday and start the real work," she said.

Hatrick said that in past years, some families have eased back into the year, too, drifting into school over the first week. With the late start, the superintendent said that must change.

"I really expect everybody to be front and center on Sept. 7," he said.