According to surveys, most Boston parents want their kids to start school somewhere between 8 and 8:30 a.m. Boston Public Schools plans to shift high school students’ schedules next year so they start class during this sweet spot. Parents, on the whole, haven’t objected to that change, since research shows high school students do better with more sleep.

To shift the start time of high school students, the district said it had to move up the morning bell for elementary school students to as early as 7:15 a.m. Some parents didn’t like that; more than 80 parents, students and officials signed up to complain at last night’s meeting of the Boston School Committee.

 “I would like you to know that I’m not angry. I’m disappointed,” Susan Lombardi-Verticelli told the school committee. “I’m disappointed because once again, you asked us what we wanted. And you went ahead with what you wanted. What you didn’t do was think about elementary school children at the bus stop at 6:30 in the morning.”

Lombardi-Verticelli’s daughter attends the Hernandez K-8 school in Roxbury. Other parents said they were worried about how their kids would grow tried throughout a long day.

“If this goes through,” Gisele Pena said, pointing to her elementary-aged daughter. “And she has to wake up at six to get to school at 7:15, by 3 o’clock she’s going to be napping in after-school [programs], and that’s not what I want for my kid.”

Antonia Rodriguez, a single mother, said she was worried about what her kids will do after they get out of school earlier in the afternoon.

“You said there was going to be support for after-school. There’s no support for after-school now,” she said. “My five kids can’t get into after-school programs now because I can’t afford it. So, who’s going to pay for it?”

As Superintendent Tommy Chang explained the logic behind the plan, some parents in the audience jeered or booed.

“Transportation is clearly a major factor in all of these scheduling changes,” he said. “We have heard time and time again that BPS spends too much money on transportation. In order to achieve meaningful, positive system-wide change, it is not possible to change bell times without having an impact on the majority of schools.”

Chang mentioned another consideration. The old way of scheduling start times has privileged white students in elementary school, he said. Right now, only 10 percent of white students attend school before 8 a.m., whereas 31 percent of black students and 27 percent of Latino students go to school that early.

Chang told the mostly white group of parents that the new assignment system, done by an algorithm, will be more fair. Just under half of elementary school students from each racial-ethnic group will start school before 8 a.m., according to the Boston School Department.

“Next year, this will be more racially balanced because race was not used as a factor in the scheduling of new start times,” he said.

Chang and School Committee members acknowledged there’s little research about the educational impact that starting school so early has on elementary school students.