A private school will become the first in the country to delay the start of lessons until 1.30pm so that teenagers can have a lie-in.
Hampton Court House in Surrey will start classes in the afternoon after research found teenagers had a 'biological disposition to going to bed late and struggling to get up early'.
From September, it will introduce a new timetable for all sixth-formers running lessons from 1.30pm until 7pm.
Head teacher Guy Holloway said this wasn't because teenagers were lazy but because the school wanted to make the most of the pupils' time in classes every day.
Mr Holloway said: "As I drove to school this morning, I saw a whole line of teenagers with bleary eyes, staggering like zombies along the pavement to another school.
"We've all seen it and, for some reason, we've all put up with it. Then we wonder why teenagers are prone to being grouchy and uncommunicative."
He added: "There is now more and more scientific evidence to support what many parents and teachers have known for years.
"The fact is that many teenagers do not sleep sufficiently during the week and this can, and often does, have a significant impact on teenage cognition and mental and physical health generally."
It isn't the first school to react to teenagers' body clocks.
The Hugh Christie Technology College in Tonbridge, Kent, introduced an 11.30am start three days a week start for all pupils aged over 14 and Monkseaton High School, North Tyneside, moved its 9am start to 10am.
Both schools say the later start has boosted pupils' concentration levels and raised exam performance.
But Hampton Court House, a day school, which charges up to £15,591-a-year, is believed to be the first to operate a 'no mornings' rule for pupils aged 16 to 18.
The move will coincide with the opening of the school's sixth form in September – the first time it has accommodated older pupils.
Mr Holloway said the change to afternoon starts for sixth formers would enable them to avoid rush hour traffic on the way to and from school.
He said: "Teenagers are not lazy. It's rare that I meet a teenager who is not full of hope and excitement about the future, so why do we berate them when they struggle to get up in the morning, in an attempt to override their circadian rhythms?
"No wonder too many older adolescents and those in their early 20s are reliant on coffee, and prone to sleep disorders and depression."
He added: "So far there has been great support for the idea amongst our parent body, and especially from prospective parents, and for us this is the main thing."
What do you think about teenagers starting school later? Does it make sense or silly as they will have to wake up for work eventually?
More on Parentdish: Surviving Teenagers: Why no one talks at breakfast