The difference between biological time (internal clock) and social time (school and work hours) is called social jetlag. We have a problem with society’s current time rhythm, in which 83 percent of the population interrupts sleep to adapt to school hours and working hours. More than half of us are late chronotypes, B-persons, and even more have daily social jet lag. If there is a five-hour difference between when you get up on school/work days and when you get up on days off, you have five hours’ social jetlag. It is in this category that we find 60 per cent of smokers. By comparison, ten percent of smokers are found in the section of the population that does not experience social jetlag. Research shows that for every hour of social jetlag, the risk of obesity increases by 33 per cent. Our society is arranged in such a way that the sleep of 80 per cent of the population is interrupted by an alarm clock.

  • It would be advisable to reduce the amount of social jetlag by adjusting the starting times of schools and workplaces to match human chronotypes.
  • It would be advisable to abandon the application of summer “daylight-savings” time, as it contributes to increased social jetlag in the population.

Only one percent of the population has a biological sleep window centered at 2 o’clock at night, and with a need for sleep of 8 hours, that corresponds with a sleep window in the period between 22-6. In contrast, the most common sleep center in the population is at 4 o’clock at night. With a need for sleep of 8 hours, it will correspond to a sleep window from midnight to 8 o’clock in the morning. In other words, the majority of us wake up if we are allowed to live in step with our natural rhythm, at 8 o’clock. And the meeting time in schools and at work should be pushed forward 1 to 2 hours, to support the biological circadian rhythms of as many people as possible. Doing so will reduce the incidence of social jet lag, which means better health, higher quality of life, and more ability to focus and be productive. For society, there will be huge savings by creating a new time architecture that supports all chronotypes. The current social time structure was created for early chronotypes, which obviously suited the society of the past times. The social architecture of the future can be designed as spacious and flexible.

It should be a fundamental right to be able to live and work in step with one’s inner clock. Imagine being able to sleep during the time your chronobiological sleep window opens up. Imagine being full of energy during the waking hours of the day. The more our biological clock is out of sync with the social time structure of society, the greater social jet lag we all suffer. It’s about creating a world, where inclusiveness and recognition also include respect for the way you sleep, wake up, go to work, live with your family, i.e. respect for your circadian rhythm. The fact is that late chronotypes are discriminated against both in the education system and in the labor market. There is only equality between the chronotypes when the exams are placed in the early afternoon and when chronodiversity becomes an integral part of the work culture.