The National Physical Laboratory of India (NPL) which is India’s official timekeeper and which manages IST (Indian Standard Time) has suggested in a recent study two time zones for India which will be called IST-I and IST-II with a difference of 1 hour between them. The study is published in the journal Current Science.

Proposal of Two Time Zones in India

Proposal of Two Time Zones in India

What are the recommendations?

The eastern states of India had been demanding for an additional time zone since a long time. At present, India follows a single time zone called IST which is (UTC+5:30) i.e 5 hours 30 minutes ahead of the international time standard. This time zone represents the longitude passing through 82°33′E.

What are the reasons for recommendation of two time zones?

Cesium Fountain Frequency Standards (Council of Scientific and Industrial Research, New Delhi)

Cesium Fountain Frequency Standards (Council of Scientific and Industrial Research, New Delhi)

Inside the northeast areas of India, the sunrise and sunset is way ahead of the standard operating time which follows the Indian Standard Time (IST). In winter months, the daytime hours are additionally reduced because the sun sinks much early. It has damaging effects on work flow and electrical power usage.

Actually, tea landscapes of Assam since long time have been already sticking with Chaibagaan Time which usually is 1 hour ahead of IST. To be able to get over complications in dealing with IST, parliamentary bodies and several other organizations within the location, the north-eastern states of India had been demanding for a separate time zone since long time.

Digging deeper into the study

The study noted the timings of sunrise and sunset of 10 different locations across India.

  1. Dong
  2. Port Blair
  3. Alipurduar
  4. Gangtok
  5. Kolkata
  6. Mirzapur
  7. Kanyakumari
  8. Gilgitum
  9. Kavaratti
  10. Ghuar Mota

From the study, it came out that the time difference between Dong (ultimate East) and Ghuar Mota (Ultimate West) is roughly 2 hours. It further stated that the current IST is very favorable for Kanyakumari, Kavaratti and Ghuar Mota, somewhat workable for Alipurduar, Kolkata, Gangtok, Mirzapur and Gilgitum but highly inappropriate for Dong and Port Blair.

The study considered several factors to determine suitability like effects of sunrise and sunset timing – on biological routines of men and women, on office time management, on spatial minimisation of time differences at the border of the two time zones, on practical possibility and difficulties of controlling two time zones.

D. K. Aswal
The demarcation line will pass through the border of West Bengal and Assam and will be very narrow. Only two railway stations – New Cooch Behar and Alipurduar – will need to be managed for time adjustment. Since the signaling system is not fully automatic, two time zones will not cause any disruption in railway operations.

We have the capability to provide two Indian Standard Times to the country. Two time zones will allow us to align standard time with daylight time.

Publisher: India Science Wire

The Research Team at National Physical Laboratory (NPL)

The research group which conducted the study had several persons as team members which involved :

  • D. K. Aswal
  • Lakhi Sharma
  • S. De
  • P. Kandpal
  • M. P. Olaniya
  • S. Yadav
  • T. Bhardwaj
  • P. Thorat
  • S. Panja
  • P. Arora
  • N. Sharma
  • A. Agarwal
  • T. D. Senguttuvan
  • V. N. Ojha

The National Physical Laboratory of India called NPL is the official measurement standards laboratory of India located in New Delhi. It works to maintain the standards of SI units in India. The lab performs its activities under the control of Council of Scientific and Industrial Research (CSIR). It is accountable for creation and distribution of Indian Standard Time (IST).

Time and Frequency Division (National Physical Laboratory of India, New Delhi)

Time and Frequency Division (National Physical Laboratory of India, New Delhi)

The laboratory has very accurate Cesium (Cs) atomic clocks and a Hydrogen Maser which is so accurate in measuring time that it has an error rate of ± 1 second per 3 lakh years. The clocks are synched with the UTC at International Bureau of Weights and Measures (French: Bureau international des poids et mesures (BIPM)) of France.

To maintain the second time zone, NPL will need to construct another lab in some northeast location which will be synched with UTC.