Giving teenagers more time to sleep helps boost their concentration levels, and consequently grades in school, according to a leading head teacher.
Dr Paul Kelley, head of the successful Monkseaton Community High in North Tyneside, has urged other schools to change their timing to 11 am.
Studies have shown that young peoples' brains are wired differently to adults'.
A research led by Professor Russell Foster, chairman of Circadian Neuroscience at Brasenose College, Oxford, showed that students' brains work better in the afternoon.
Foster revealed that body clocks shifted as children enter their teen years, many got up late as they were biologically programmed to do so and not because they were lazy.
Kelley said that lack of sleep could affect pupils' mental and physical well-being as well as their education.
"Teenagers aren't lazy. We're depriving them of the sleep they need through purely biological factors beyond their control," The Telegraph quoted him as saying.
"The research carried out by Professor Foster showed that, from the age of 10, our internal body clocks shift, so it's good for young people to stay in bed. They peak at 20 then gradually go back again, but body clocks do not reach the pre-teenage level until around 55 years old. The 'time shift' is two hours on average, so teenagers should get up two hours later. We are making teenagers ratty by getting them up early," he added.
Last year, students of Kelly's school scored up to 90 per cent in a GCSE science paper after just an hour of teaching. They were given three 20-minute bursts of intensive teaching with slides, interspersed with 10-minute breaks for physical exercise.