Britain's adult population is getting just as much sleep as it was nearly 40 years ago, according to research.
Not such a rare commodity
The findings contradict the popular belief that we live in a sleep-deprived society, getting less rest than our parents or grandparents used to.
The Surrey Sleep Research Centre survey of almost 2,000 adults found most sleep an average of seven hours a night - virtually the same as in the mid-1960s.
The study is published in the Journal of Sleep Research.
Professor John Groeger, who led the study, said although some people may not be getting all the sleep they need, there is little or no proof that the population as a whole is sleeping less.
"It's very hard to find any evidence that we live in a sleep-deprived society," he said.
"But it's clearly something that's discussed a great deal in the media."
The dangers of sleep deprivation are now considered a major health hazard.
Earlier this month, a lorry driver was jailed for 18 months after killing a 20-year-old woman when he fell asleep at the wheel of his 17-tonne truck on a road in Somerset.
Average night's sleep is 7.04 hours
36% have trouble getting to sleep
20% have trouble getting up on time
Married men sleep less than married women
80% are in bed between 10pm and 1am
5% sleep less than five hours
6% sleep more than nine hours
Road safety experts now believe tired drivers may account for more accidents than drunk drivers.
With more shift work, longer trading hours and round-the-clock supermarket facilities, Britain and many other developed countries are moving towards a 24-hour society.
But while concerns mount about the damage to health from too little sleep, experts say there have been few in-depth studies examining whether sleep patterns have really changed down the years.
The Surrey University team analysed data from 1,997 people aged from 16 to 93.
Each participant was questioned face-to-face on all aspects of their sleeping habits, from what time they normally went to bed, to whether they slept more than their partners or lay in bed at the weekends.
Although there were tremendous variations between age groups, the average night's sleep worked out at 7.04 hours.
When the researchers compared that with a similar survey published in the late sixties, they found little or no change.
However, Professor Groeger stressed that some people may actually need more sleep these days because of the way society has changed.
"There is evidence that working hours have increased and that there's more round-the-clock working.
"So although there's no evidence that sleep duration has changed, the implication is that modern life is substantially more demanding.
"So if the demands on us go up, then the need to rest also increases."
The survey confirmed that teenagers sleep longer than anyone else - averaging at least an hour more than the general population - and that the older people get the less sleep they need.
But it also raised some unusual findings. Married men claim they sleep less than their married partners, one in three people have trouble getting to sleep at night and nearly half of us wake up at some point during the night.
British Sleep Society chairman Neil Stanley said it is hard to get an accurate picture of how sleep patterns have changed, since historical data are not good quality.
"It's difficult to really say if we are sleeping less or more. But I do think we are putting more mental strain on ourselves, rather than physical strain.
"We now know that sleep is mainly for the brain not the body and we do live in an age of information overload compared to years ago."