Should India have two time zones?


  • OVER THE years, various citizens and political leaders have debated whether India should have two separate time zones. The demand is based on the huge difference in daylight times between the country’s longitudinal extremes, and the costs associated with following the same time zone.
  • Those arguing against the idea, on the other hand, cite impracticability — particularly the risk of railway accidents, given the need to reset times at every crossing from one time zone into another.
  • Now, a proposal for two time zones has come from India’s national timekeeper itself. Scientists at the Council of Scientific & Industrial Research’s National Physical Laboratory (CSIR-NPL), which maintains Indian Standard Time, have published a research article describing the necessity of two time zones, with the new one an hour ahead of the existing time zone.
  • Published in Current Science, the article adds new arguments to the debate. It identifies where the two time zones be demarcated from each other — at the “chicken neck” that connects the Northeast to the rest of India, an area that is spatially narrow and reduces the possibility of railway accidents, it says. The article also puts a figure to the country’s potential savings in energy consumption — 20 million kWh a year — if it does follow two time zones.

A look at the debate, and the new suggestions:

How time is maintained

  • If lines of longitude are drawn exactly a degree apart, they will divide the Earth into 360 zones. Because the Earth spins 360° in 24 hours, a longitudinal distance of 15° represents a time separation of 1 hour, and 1° represents 4 minutes. Theoretically, the time zone followed by any place should relate to its longitudinal distance from any other place. Political boundaries, however, mean that time zones are often demarcated by bent lines rather than straight lines of longitude. This is “legal time”, as defined by a country’s law.
  • The geographic “zero line” runs through Greenwich, London. It identifies GMT, now known as Universal Coordinated Time (UTC), which is maintained by the Bureau of Weights and Measures (BIPM) in France.
  • Indian Standard Time, maintained by CSIR-NPL, is based on a line of longitude that runs through Mirzapur in UP. At 82°33’E, the line is 82.5° east of Greenwich, or 5.5 hours (5 hours 30 minutes) ahead of UCT. While India follows one IST, the United States follows several time zones across its breadth.

The India debate

  • India extends from 68°7’E to 97°25’E, with the spread of 29° representing almost two hours from the geographic perspective. This has led to the argument that early sunrise in the easternmost parts — the Northeast — causes the loss of many daylight hours by the time offices or educational institutions open, and that early sunset, for its part, leads to higher consumption of electricity.

  • In March, in reply to a question in Parliament, the government said it has not taken any decision on separate time zones. A committee set up in 2002 did not recommend two time zones because of the complexities involved, the government said. It had cited the same committee’s findings in the Gauhati High Court, which last year dismissed a public interest litigation seeking a direction to the Centre to have a separate time zone for the Northeast.

The new findings

  • The research paper proposes to call the two time zones IST-I (UTC + 5.30 h) and IST-II (UTC + 6.30 h). The proposed line of demarcation is at 89°52’E, the narrow border between Assam and West Bengal. States west of the line would continue to follow IST (to be called IST-I). States east of the line — Assam, Meghalaya, Nagaland, Arunanchal Pradesh, Manipur, Mizoram, Tripura, Andaman & Nicobar Islands —would follow IST-II.
  • The paper explains the choice of the line: “As the railway signals have not yet been fully automated in the country, the border between the two time zones should have a very narrow spatial-width with minimum number of train stations so that the train timings while crossing the border can be managed manually without any untoward incidents.”
  • The researchers estimated energy savings at 20 million kWh a year based on a formula explained in the article. They also analysed the importance of synchronising office hours — as well as biological activities — to sunrise and sunset timings.
  • To make the idea possible, CSIR-NPL would need a second laboratory in the new time zone. This would consist of ‘Primary Time Ensemble-II’, traceable to the UTC at BIPM in France.
  • While the article asserts that CSIR-NPL already has the technical expertise to duplicate its existing facility, it also acknowledges that the move would require legislative sanction.


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