Daylight saving time can be harmful.

Researchers have previously not thought that an hour´s change could make noticeable difference.

Daylight saving time may particularly affect our quality of sleep.

It can also affect our wakefulness and performance during the day.

The body has an inherent daily rhytm of approximately 24 hours.It´s seasonal and dependent on the sunshine during the year.

There are also genetic factors that make us more alert in the morning or in the evening.

Daylight saving time means that local time is adjusted forward one hour near the start of spring and is adjusted backward in autumn.

Daylight saving time is used in about 70 countries around the world,more than half of them are in Europe.

In the tropic and in countries near the poles,daylight saving time is unusually.

It´s beacuse that the difference between summer and winter is less.