Tonight may be the last time we go to summertime. When the time adjustment is abolished, we must decide whether it should be winter or summer time.

Dark mornings

Opinion surveys have shown that many want summer time all year long. That would mean it gets dark one hour longer during the winter mornings, and that's when we need the light most.

- The morning light signals to the brain that the day has begun and it is important for our physical systems to be regulated in a good way, says Arne Lowden, a sleep and stress researcher at Stockholm University.

Important light pulse

When the brain gets the pulse of light in the morning, we become energized, able to perform, and we get energy. The body stays awake until it's time to start getting tired again until the evening. With summer time in winter it would instead be an hour brighter in the afternoon.

- The bright afternoon hours do not produce the same biological effect at all, he says.

The extra hour later in the day can also delay our sleep phase, get us to go to bed later, and sleep less. The number of workplace accidents will increase and more people will suffer mental illness.

- Obviously, I prefer to maintain the system we have today. Then we would satisfy those who greet the summer time with joy while at the same time getting the good effects of the winter time, says Arne Lowden.

Like going to Finland

The combined research shows that there are no major medical problems with moving the clock forward in the spring and resetting it in the fall. It has just as much impact on our health as a trip to Finland, which is a time zone ahead of us.

- We have not noticed any massive complaint about people going to Finland. Moving forward a time zone is quite successful in our system, he says.

Before the Swedish government can decide whether we should have summer or winter time all year round, the EU Council of Ministers must say its own. It has been decided by the abolition of the time shift to operate from 2021.