Current Time in Sweden

A clock is a device that measures time. The first clocks were sundials, which used the position of the sun to tell the time of day.

Over time, mechanical clocks were developed, using springs and gears to move hands around a dial. Today most clocks are electronic and use quartz movements, which keep time by applying an electric voltage across a quartz crystal.

Time zones are a convention used to measure time around the world. They are necessary because the Earth rotates on its axis, creating different times of day in different parts of the world.

Each time zone is offset by hours from a standard reference, traditionally Greenwich Mean Time (GMT) in London, England. Time zones became necessary to coordinate railway travel in the 19th century.

Daylight saving time is the practice of moving clocks one hour forward or back at specific times of the year. In most countries that use it, clocks move one hour forward in summer.

This gives more daylight in the evening and saves energy, since people need less electric lighting.

Although daylight saving time can have practical benefits, there are drawbacks too. It can take a few days for the body to adjust to the new time, which may cause tiredness and sleep problems.

It can also disrupt some people's schedules, such as schoolchildren who have to get up earlier in the morning.