What is day light saving time and Greenwich mean time (describe)?

Day light saving time

During the spring term for utilization of sun light more and more there is need to change the time and that change in time nothing but a day light saving time.

When it is in existence?

Starting of 20^th century a scientist George warren Hudson idea of saving day light time.

How can we save day light time?

By increasing 1 hour in a watch during the spring and decreasing 1 hour  in a watch in summer.

70 country currently using day light saving time.

20% population of the world dependent on the day light saving time.

Greenwich mean time

A city Greenwich situated in England having a solar observatory, during the 18^th century England was named as ocean power and they have Greenwich direction detector device.

Britain starts Greenwich mean time in 1676 in Greenwich observatory centre on the basis of two similar watches.

In 1852 Greenwich time announced publicly.

In 1884 in Washington with 25 other countries Greenwich certified as Prime meridian.

Greenwich rays separate the world in east and west zone and equator separate the world in north and south pole.

World’s +ve and –ve value of time observed on the basis of Greenwich rays.

Got the UTC certificate but mostly Greenwich mean time in use.

Different time zones of the world.

Country              time zones

France                   12

America                  9

Russia                    11

Britain                    9

Australia                8

Denmark                5

China is the only one country (large in area) which have only one time zone.

Over time of sun in different places of the world.

Normally 12 hour day and 12 hour night schedule in the world but in some places there is a over time of sun.

Norway

Also known as mid night sun near the arctic circle where presence of sun almost 20 hours per day between May and July (76 days).

Finland

In the summer presence of sun almost 73 hour continuously but in winter presence of sun is almost nil.

Sweden

Here sun sets after the midnight and rise just after the 4 o’clock in the morning between starting of the May and ending of the August.

Iceland

Here sun never be fully sets continuous revolving perpendicular.