Changes

Greenwich Mean Time, or GMT is the mean time that the earth takes to rotate from noon-to-noon. <ref>http://wwp.greenwichmeantime.com/what-is-gmt.htm</ref> The Greenwich Meridian (Prime Meridian or Longitude Zero degrees) marks the starting point of every time zone in the World.

Greenwich Mean Time, or GMT is the mean time that the earth takes to rotate from noon-to-noon. <ref>http://wwp.greenwichmeantime.com/what-is-gmt.htm</ref> The Greenwich Meridian (Prime Meridian or Longitude Zero degrees) marks the starting point of every time zone in the World.

For every 15˚ change in longitude away from the Prime Meridian, there is one hours' difference in local time, compared to that at Greenwich. Towards the east of Greenwich, the local time will be ahead of GMT, whilst to the west, local time will lag GMT. This has resulted in the world being divided into 24 time zones,but also large land masses and countries being divided into several time zones.

For every 15˚ change in longitude away from the Prime Meridian, there is one hours' difference in local time, compared to that at Greenwich. Towards the east of Greenwich, the local time will be ahead of GMT, whilst to the west, local time will lag GMT. This has not only resulted in the world being divided into 24 time zones, but also large land masses and individual countries being divided into several time zones.

Although GMT has been replaced by atomic time (Coordinated Universal Time or UTC) it is still widely regarded as the correct time for every international time zone.

Although GMT has been replaced by atomic time (Coordinated Universal Time or UTC) it is still widely regarded as the correct time for every international time zone.

Allowance also needs to be made for [[Daylight Saving Time]], or Summer Time Zones, where applicable, which include an offset of an extra hour.

Allowance also needs to be made for [[Daylight Saving Time]], or Summer Time Zones, where applicable, which include an offset of an extra hour.

The International Date Line is an imaginary line running approximately between time GMT+12 and GMT-12, that separates two consecutive calendar days. The date in the Eastern hemisphere, to the left of the line - time zone M (Mike)- is always one day ahead of the date in the Western hemisphere, to the right of the International Date Line - time zone Y (Yankee).

The [[International Date Line]] is an imaginary line running approximately between time GMT+12 and GMT-12, that separates two consecutive calendar days. The date in the Eastern hemisphere, to the left of the line - time zone M (Mike)- is always one day ahead of the date in the Western hemisphere, to the right of the International Date Line - time zone Y (Yankee).

It has been recognized as a matter of convenience and has no force in international law.

It has been recognized as a matter of convenience and has no force in international law.