Standard Time and International Meridian Conference


Standard Time and International Meridian Conference (IMC)

Standard Time and International Meridian Conference (IMC) are one of the important topics in UPSC Examinations. So, I think this article will surely helpful for your Examinations.

Standard Time 

  • Before the middle of 19th century, 100’s of different time system were in use, throughout the world, based on the rising of the sun.
  • Sir, Sanford Fleming led the fight in Canada for Standard time and for an International agreement upon prime meridian. His Struggle lead, United States, Canada to adopt Standard Time in 1883.
  • In 1884 International Meridian Conference (IMC) in Washington DC, to avoid confusion. We follow uniform time throughout the country, such uniform time is based on central meridian of the country or meridian on which most important city is located.
  • Such a Central meridian is called Standard Meridian for India, 82 ½° East. Generally central meridian is taken in such a way by that it is divisible by 7½°.
  • So that the standard time differs from GMT ( Greenwich Mean Time) by multiples of half an hour.
  • Countries which have vast longitude extension do not have a standard single time for the whole country.
  • Generally such country goes for more than 1-time zone each approximately 15° of longitude.
  • China extends across 4 fifteen degrees zone, the entire nation at least officially observe the time of 120° E meridian close to china’s capital.

International Meridian Conference (IMC) 1884.

  • The world was divided into 24 standard time zones each extending over 15° of longitude.
  • The local solar time of the Greenwich was chosen as the standard for the entire system.
  • The prime meridian (PM) became the centre of a time zone that extends 7½ of longitude both to the west and to the east of the Prime Meridian.
  • Similarly, the meridians that are the multiples of 15, both cast and west of the meridian, were set as the central meridians for 23 other time zones, each of which is 15° of longitude in extent.
  • 12 zones to the east of Greenwich meridian were designated to be ahead of the time at Greenwich by 1 hour per zone. Similarly, 12 zones to the west of GreenWich are behind.
  • In International waters, these time zones are shown exactly 7½ to east and 7½° to the west of the central meridians.
  • Over land areas, however, the actual eastern and western boundaries of time zones vary to coincide with appropriate political and economic constraints.

This is the article about Standard time and International Meridian Conference


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