Indian Geography (Unit 1-Topic 2) Standard Time and Time Zones

Indian Geography (Unit 1-Topic 2)

 Standard Time and Time Zones

• If each town were to keep the time of its own meridian, there would be much difference in local time between one town and the other.
• Travelers going from one end of the country to the other would have to keep changing their watches if they wanted to keep their appoint­ments. This is impractical and very inconvenient.
• To avoid all these difficulties, a system of standard time is observed by all countries.
• Most countries adopt their standard time from the central meridian of their countries.
• In larger countries such as Canada, U.S.A., China, and U.S.S.R, it would be inconvenient to have single time zone. So these countries have multiple time zones.
• Both Canada and U.S.A. have five time zones—the Atlantic, Eastern, Central, Mountain and Pacific Time Zones. The difference between the local time of the Atlantic and Pacific coasts is nearly five hours.
• S.S.R had eleven time zones before its disintegration. Russia now has nine time zones.

The International Date Line

• A traveler going eastwards gains time from Green­wich until he reaches the meridian 180°E, when he will be 12 hours ahead of G.M.T.
• Similarly in going westwards, he loses 12 hours when he reaches 180°W. There is thus a total difference of 24 hours or a whole day between the two sides of the 180° meridian.
• This is the International Date Line where the date changes by exactly one day when it is crossed. A traveler crossing the date line from east to west loses a day (because of the loss in time he has made); and while crossing the dateline from west to east he gains a day (because of the gain in time he encoun­tered).
• The International Date Line in the mid-Pacific curves from the normal 180° meridian at the Bering Strait, Fiji, Tonga and other islands to prevent confusion of day and date in some of the island groups that are cut through by the meridian.
• Some of them keep Asiatic or New Zealand standard time, others follow the American date and time.

Why is the international dateline drawn in a zigzag manner?

• The International Date Line (IDL) passes through the Pacific Ocean. It is an imaginary line, like longitudes and latitudes.
• The time difference on either side of this line is 24 hours. So, the date changes as soon as one crosses this line.
• Some groups of Islands (Polynesia, Melanesia, Micronesia) fall on either of the dateline. So if the dateline was straight, then two regions of the same Island Country or Island group would fall under different date zones. Thus to avoid any confusion of date, this line is drawn through where the sea lies and not land. Hence, the IDL is drawn in a zig-zag manner.

Indian Standard Time

• The Indian Government has accep­ted the meridian of 82.5° east for the standard time which is 5 hours 30 mins, ahead of Greenwich Mean Time.

Chaibagaan Time

• 150 years ago British colonialists introduced “chaibagaan time” or “bagaan time”, a time schedule observed by tea planters, which was one hour ahead of IST.
• This was done to improve productivity by optimizing the usage of daytime.
• After Independence, Assam, along with the rest of India, has been following IST for the past 66 years.
• The administration of the Indian state of Assam now wants to change it’s time zone back to Chaibagaan time to conserve energy and improve productivity.
• Indian government didn’t accept to such a proposal.