As Montgomery County seeks community reaction to a proposal to shift the opening bells of high school to 8:15 a.m., allowing teens to get more sleep, surveys suggest a change of public mood on the issue since the 1990s.

Seventy percent of parents who responded to a survey in the spring said high school starting times are “too early,” according to a recently released report. About 28 percent of parents liked the current start time of 7:25 a.m.

By comparison, in 1996, more than half of high school parents who responded — 55 percent — said high schools started at the right time, with just 45 percent saying schedules were too early.

“I think there’s greater education about how important sleep is,” said parent Mandi Mader, who launched a petition last year to shift the high school schedule. Research and public awareness have increased, she said, and in Montgomery, “it hit a nerve.”

Superintendent Joshua P. Starr in December created a study group to examine research and outline possibilities for change, and Starr unveiled a proposal Oct. 1 to rearrange schedules so that high schools would start 50 minutes later than they do now.

His proposal is expected to undergo a lengthy period of public examination and response.

In a survey of students earlier this year, 63 percent said classes started “too early.” Fifty-four percent of students favored a schedule that would start 30 minutes or an hour later, with 38 percent of students saying school hours should stay the same.

With a later start to the high school day, 85 percent of students said they would expect to get more sleep.

Hinting at possible trade-offs, about one-third of students said it would be more difficult to get a job or participate in sports and activities.

In recent surveys, 44 percent of parents cited a positive effect on student safety, and more than 60 percent of parents said a later start time would improve their child’s grades, health, happiness and school attendance.

More than 70 percent of parents did not expect an impact on child care or teen jobs, but nearly one in four said a schedule change would negatively affect after-school activities and sports practices.

The survey also gave a glimpse inside the classroom: One-third of students said they dozed off or lost focus in early classes two to four times a week, and an additional 30 percent said they did so every day.

Fifty-five percent of students said they got six hours or less of sleep a night. Researchers say teenagers need 81 / 2 hours to 91 / 2 hours nightly and that sleep deprivation is linked to problems such as obesity, depression and car crashes.