How do you tell time in different places on the earth?

Answer 1

Look up, and when the sun is halfway across the sky between east and west it is 12 noon local time. Well, the above is true from both a practical and scientific standard, but not always true in a political sense. For example: China is wide enough from east to west that it really should have four time zones, but for political reasons the Chinese government decided that the whole country would have just one time zone. see the Related Link below for a map of world time zones.

Answer 2

Time has from beginning of time been calculated with the help from the sun.

When it becomes light, the day starts. When it get dark, the day ends.

In the early years, we just used a stick in the ground and its shadow as the indicator for what time it was.

As societies grew, we made mechanical instruments in order to also tell time during the night. Not very accurate in the beginning, but man strives for perfection.

When the clocks started to become common, the societies started to rely more on them. Simple terms as light or dark was not enough. Man had to go to work at specific times, not only when it was light enough to do work. Early in the mornings, we created our own light in order to do more work.

As time of sunrise changes very much during the days in the year, we have (on northern and southern part of our earth) less or more daylight depending on which day, week, month, season it is.

During summer we have more light, and during winter we have less light.

In today's societies of watches and timekeeping schedules, we follow the clock. The old days of only following the light has gone.

During war, it was suggested to save energy by using daylight better. This was instated by shifting the clock one hour back in order to get more out of the daylight during summer, and vice versa one hour forward during winter.

Some countries do not use DST (Daylight Saving Time), where as other countries do. All of this together adds to the complexity of telling the time in different places on the earth.

It is however generally accepted all over the world that when the stick in the ground leaves the shortest possible shadow during the day, the time is 12, and the we add or deduct the hour of DST for countries who follow this.