Last Friday, mothers and fathers could be seen around Alexandria's Del Ray neighborhood, walking hand in hand with their children in the annual ritual of going to school to meet their teachers in preparation for the first day

Unlike in years past, the return to school this year was not marked by falling leaves or cool breezes. This week, while most kids were still in summer camp or hanging around at home, Mount Vernon Elementary School became the second school in Alexandria to switch to a modified calendar that shortens summer vacation to around a month and adds vacation time during the school year.

On Friday, students attended an open house to meet their new teachers in preparation for Monday, when -- as a large banner outside the school reminded everyone -- classes would begin.

Principal Lulu Lopez greeted students at the door, giving exuberant hugs to returning students and their parents, switching languages depending on who walked in: "Good morning. . . . Bienvenido. . . . Nice to see you. . . . Are you happy to be back?"

Yolanda Salazar stood in her son David's new first-grade classroom and watched him name colors and shapes from charts on the wall as his new teacher, Barbara Kirkland, smiled encouragingly. His sister Ashley, a third-grader, showed off her tae kwon do skills.

"I love it," Salazar said of the modified calendar. "They're very excited, they're ready." The family had gone to Target and Wal-Mart the day before for school supplies, she said, getting there before most families in the area arrive in late August to pick the stores bare.

Salazar, who works full time as a loan officer, said the schedule would add quality time to her children's lives, giving them a place to study and socialize "rather than sitting around watching TV and waiting for me to get home."

Other parents wandering the school's halls echoed that sentiment, saying that by August they have often run out of activities for their children.

Besides keeping kids occupied, supporters of the change say, the modified calendar reduces the amount of academic information the kids forget over the summer and must relearn. This is especially true for the 53 percent of Mount Vernon's students who are learning English as a second language and may not hear a lot of it spoken at home, Lopez said. She added that the modified calendar would also help the 120 students in Mount Vernon's dual-language program, in which instruction takes place in English and Spanish.

The school year will proceed in nine-week blocks, with two-week breaks in the fall and winter and a three-week break in the spring. During the breaks, students can opt to take "intersession" courses, either for remedial work or to pursue "enrichment" subjects -- such as foreign languages, drama or cooking -- that the school does not have time to offer during the regular school year.

Proponents praise the idea of students who need remedial work getting it throughout the year, rather than waiting until summer school, and they note that the arrangement allows families with relatives abroad to travel outside the country more easily during the school year.

Lopez, who previously was principal of two schools in Los Angeles that had year-round calendars, said she and Alexandria Schools Superintendent Rebecca L. Perry began discussing the possibility of a modified calendar in 2001. She and staff members and parents spent time atFairfax and Arlington county schools that had made the switch. (In Arlington, one school -- Barcroft Elementary -- adopted the modified calendar two years ago. Its classes begin today.)

Two years ago, a survey of parents at Mount Vernon did not yield the 70 percent minimum vote needed for the change to be made. Last year, however, the threshold was met (in both years, more than 80 percent of teachers at the school voted for the change).

But relations were not always congenial in the months leading up to those votes. Some parents said the proposal to switch to a modified calendar had driven a wedge into a formerly tightly-knit school community.

Ultimately, the parents of 20 to 25 students switched their children to other Alexandria schools because of the change. In some cases, they cited the difficulties for families with children in middle or high schools that did not have the same schedule.

Tamar Powers, a former PTA officer at Mount Vernon who is moving her son to George Mason Elementary School, was one of the parents opposed to the change.

"I could not fathom saying to one child in August, 'Well, you have to go to bed because it's a school night' and then turning to the other one and saying, 'But you get to stay up.' I can't imagine the toll that that would take on my family," she said.

Opponents also questioned the cost to the school system -- an additional $396,877 per year -- for a plan they say limits their children's nonacademic summer activities, has not been proven to boost academic skills and amounts to little besides free baby-sitting.

"In my opinion, it's year-round day care," said Karen Lemke, who is moving her children to Maury Elementary School because of the change. As a teacher at a preschool with a traditional calendar, Lemke said, the modified calendar would have put her on a schedule that would have been completely different from her children's.

"Basically, it disrupts many lives," she said. "Life is already so complicated in Washington, D.C., and surroundings, why do we have to complicate it any further?"

As debate raged last year among members of the school community, Lemke said, some defined the divisionalong ethnic and socioeconomic lines. Families that could afford summer camp or long vacations were accused of ignoring the needs of other families, many of them poor and Hispanic, that couldn't afford such things, she said.

"They were pitting people against each other, saying basically you were racist because you didn't support the modified calendar," Lemke said. "It caused such a divide that was not there before."

Powers agreed. "It was always highlighted as a racial issue," she said, "that 'you middle-class parents, you homeowners, you're being selfish,' that the need for a long summer break is a middle-class myth."

But Larry Campbell, a parent who sat on the school's task force that studied the modified calendar and moved his children out of Mount Vernon last year because of the possible change, said summer break can offer much that school cannot.

"Public school, it's a wonderful experience, but it's not an experience that we want our children involved in 11 months out of the year," he said, adding that his children participate in church, Girl Scouts and family activities during summer. "That diversity of experience is important to them."

Cathy David, the Alexandria school system's assistant superintendent for curriculum and instruction, said the differences in the process at Mount Vernon and at Samuel W. Tucker Elementary School, which adopted a modified calendar a year ago, were striking.

"At Tucker, it was just a handful of parents who chose to opt out," she said. "At Mount Vernon, there were more who felt very strongly about the full summer vacation."

Lopez agreed that tensions rose last year. "Unfortunately, some feelings may have been hurt in the process, and that certainly wasn't our intent," she said. "Enough staff members felt that this was really something we should do."

At the school on Friday, teachers and parents seemed enthusiastic about the change. Kindergarten teacher Teresa Breakwell said she took the job at Mount Vernon this year because of the modified calendar, which was similar to the one used by her last school, Parklawn Elementary in Fairfax County.

There, at the beginning of each year, "you didn't have to spend the first nine weeks basically teaching classroom behavior and expectations," she said. "We could get right into academics." Breakwell added that the schedule worked better for her personal life, too.

But Melanie Needels, who teaches second grade at Mount Vernon and has a third-grade son there, said she voted against the change because she did not like the idea of shortening her summer vacation. Still, the new schedule was not enough to make her change schools, as a few teachers did.

Needels said that despite her own shortened summer she saw a lot of good in the program. At other modified-calendar schools she visited, "the intersessions seemed really exciting," she said. "The kids, you could tell that they loved being there. And the fact that the remediation was in the middle of the year really seemed to help."

Jim Schwartz, a parent who was president of the school's PTA last year, said so many teachers' being in favor of the plan helped convince him to support it. He added that the change might benefit Mount Vernon students competing in a global market, where education is increasingly important.

Noting that long summer vacations were devised in a more agrarian age so that children could help with planting and harvesting on family farms, he said, "We have to start getting serious about [competing] and stop trying to fit ourselves into a calendar that was built for a different time."

Lulu Lopez, above center, principal at Mount Vernon Elementary School in Alexandria, greets Jennifer Greiner of Alexandria, far right, and her daughter Lila, 5, while Katherine Carraway of Alexandria and her children Emma, 7, and Nick, 5, watch during an open house for students and families on Friday. The school has begun using a modified schedule this year, shortening summer vacation and adding vacation time during the school year.

Camila Cardwell, 5, listens as her mother, Devin Reese, reads "The Night Before Kindergarten" at Mount Vernon Elementary School.

First-grader David Salazar, 6, reads the names of shapes displayed on a hanging banner as Kathy Salazar holds 2-month-old Aryana. Behind them, dual language program instructors Barbara Kirkland and Denise Santiago, from left, and Yolanda Salazar, David's mother, track his progress. "I love it," Yolanda Salazar said of the school's modified calendar. Above, Lily Morton, 4, and Lila Greiner peer through the windows of their classroom's playhouse.Ashley DesRochers points out shapes and numbers on a play mat to Phoebe LaMountain, 4. Adopting a new schedule will cost the school system $396,877 per year. Parents moved as many as 25 children to other schools because of the change, some because they had other children in schools with traditional schedules.