Two time zones debate

Also called: Multiple time zones debate, Two time zones for India · Topic: Latitude, Longitude and Time · NCERT: Class 11, Ch 1 "India - Location"

Meaning

The two time zones debate is the long-running argument over whether India should keep one clock time, Indian Standard Time (IST), or add a second, earlier time zone for the north-east. The reason is that the sun rises there about two hours earlier than in Kutch, Gujarat.

It matters because one clock across a very wide country wastes morning daylight in the east, raises evening power use and upsets people's sleep. On the other side, one national time keeps railways, markets and the country working together.

Explanation

How the problem forms: one clock for a wide country

• The Earth turns 1° every 4 minutes.
• It turns 360° in 24 hours.

• So each degree of longitude (the lines running from pole to pole) means 4 minutes of difference in local sun time.

• India is very wide from west to east.

• It runs from 68°7′E (Kutch, Gujarat) to 97°25′E (Arunachal Pradesh). That is about 29° of longitude.

• 29° × 4 minutes ≈ 116 minutes. That is nearly two hours of solar time (time measured by where the sun is in the sky).

• But the whole country reads one clock.

• IST is the local time of the standard meridian (the one line of longitude a country chooses for its clock time) at 82°30′E, near Mirzapur, Uttar Pradesh.
• 82.5° × 4 minutes = 330 minutes, so IST = UTC + 5:30. UTC (Coordinated Universal Time) is the world reference time kept by atomic clocks.
• Result: the sun rises and sets in the north-east about two hours earlier than in Kutch, yet both places show the same time.

Effects in the north-east

• Morning daylight is wasted.
• In summer the sun rises at about 4 a.m. in Dong valley.

• Offices and schools open many hours later.

• More electricity is used in the evening.

• In winter the sun sets around 4:30–5 p.m.

• Homes and offices need lights on for longer.

• The body clock is upset.

• Working hours do not match the natural day-night rhythm.

• People already use a local fix.

• Chai bagaan time ("tea garden time"): since British times, Assam's tea gardens have kept their own clock about one hour ahead of IST, so work starts and ends with the early daylight.
• It has no legal standing. It is only a custom of the tea estates.

The arguments and the proposals

• Time zone: an area that keeps the same standard time.

For a second zone	Against a second zone
Saves daylight and energy, because less evening lighting is needed	Risk of railway and air-traffic mistakes where the two zones meet
Better productivity, because work hours match daylight	Confusion in a closely linked national economy (markets, banking, TV schedules)
Better health and sleep	Symbolic value of one national time for unity
Long-standing north-east demand, raised by Assam's Chief Minister in 2014	Cost of resetting systems, and constant switching at the zone border

• Proposals made:
• In Parliament: a Lok Sabha member from Nagaland proposed an Eastern Indian Time (one hour ahead, from Arunachal Pradesh to Bihar) and a Western Indian Time (from Uttar Pradesh to Gujarat) [4].
• NPL researchers (Current Science, 2018):
  • IST-I = UTC + 5:30 for most of India.
  • IST-II = UTC + 6:30 for the north-east and the Andaman & Nicobar Islands.
  • The two zones would be divided near 89°52′E, roughly the West Bengal–Assam border.

• Middle path: move IST for all of India forward by half an hour, to UTC + 6:00. India keeps one zone, and the east gets more useful daylight.

• Present position:

• The Union government has not accepted a second zone, so India still follows a single IST.
• The Legal Metrology (Indian Standard Time) Rules, 2026 make IST the one legal, common time reference for the whole country, under the vision of "One Nation, One Time" [2].

Where it occurs

• North-east India: this is the region that would get the proposed second zone. Assam's Chief Minister raised the demand in 2014, and a Lok Sabha member from Nagaland raised it in Parliament [4].
• Dong valley: in Anjaw district, Arunachal Pradesh, near the India–China–Myanmar trijunction (where the three borders meet). It is India's first sunrise point, at about 4 a.m. in summer.
• Assam's tea gardens: they keep chai bagaan time, about one hour ahead of IST.
• Kutch, Gujarat (68°7′E): India's western edge. The sun rises here about two hours later than in Arunachal Pradesh.
• Porbandar (Gujarat) and Tinsukia (Assam): the Class 6 example. Their local times differ by well over 1½ hours, but both read the same IST.
• Proposed dividing line: about 89°52′E, near the West Bengal–Assam border. The proposed IST-II would also cover the Andaman & Nicobar Islands.
• 82°30′E meridian (the IST line): passes near Mirzapur and crosses Uttar Pradesh → Madhya Pradesh → Chhattisgarh → Odisha → Andhra Pradesh.
• Who keeps IST: CSIR-National Physical Laboratory (NPL), New Delhi, uses an ensemble of atomic clocks (a group of clocks working together). IST is sent out through five Regional Reference Standard Laboratories at Ahmedabad, Bengaluru, Bhubaneswar, Faridabad and Guwahati [2].
• World: large countries such as Russia and the USA have several time zones.

Don't confuse with

• Chai bagaan time: a local custom of Assam's tea gardens, about 1 hour ahead of IST, with no legal standing. The proposed IST-II would be an official second time zone.
• Shifting IST by 30 minutes: India would keep one zone, moved to UTC + 6:00. The two-zone plan keeps UTC + 5:30 for most of India and adds UTC + 6:30 for the east.
• Local time vs standard time: local time follows the sun at each place and changes by 4 minutes per degree of longitude. Standard time (IST) is one clock time for the whole country, taken from the 82°30′E meridian.
• "One Nation, One Time" (Legal Metrology IST Rules, 2026): these rules make the single IST the legal time reference [2]. They do not create a second zone.

Prelims Hooks

• India spans about 29° of longitude (68°7′E to 97°25′E), which gives about 2 hours of solar time difference between Kutch and Arunachal Pradesh.
• The proposed IST-II = UTC + 6:30, for the north-east and the Andaman & Nicobar Islands, with the dividing line near 89°52′E (NPL researchers, Current Science, 2018).
• Trap: the Union government has not accepted the two-zone proposal. India still has one IST (UTC + 5:30).
• Dong valley is in Anjaw district, Arunachal Pradesh, and is India's first sunrise point (about 4 a.m. in summer).
• Chai bagaan time in Assam's tea gardens runs about 1 hour ahead of IST and has no legal status.
• Trap: IST was introduced in 1906, but Calcutta Time lasted until 1948 and Bombay Time until 1955.

Mains Points

• Regional problem (GS-I): one clock across 29° of longitude causes several problems in the north-east.
• Sunrise and sunset come early, so morning daylight is wasted.
• Evening power demand goes up.
• People's body rhythms are upset.
• It adds to a feeling of distance from the "mainland".

• Assam's chai bagaan time shows that a local fix already works in practice.

• Policy trade-off: a second zone (IST-II at UTC + 6:30) could save energy and raise productivity.

• Against it are safety risks for railways and aviation at the zone border, and confusion in markets and banking.
• Middle paths: move IST forward by 30 minutes, or change office hours in the north-east without changing the clock.

• The demand comes from the Assam Chief Minister (2014) and members of Parliament [4], so it is a federal question. Any decision needs Centre–state consultation.

• Infrastructure (GS-III): power grids, telecom/5G, banking and navigation all need exact time.

• The Legal Metrology (IST) Rules, 2026, NPL's atomic clocks and the five RRSLs build one national timing system for "One Nation, One Time" [2].
• The draft rules asked for millisecond-to-microsecond accuracy, with government networks kept on IST through NTP/PTP (standard ways for computers to set their clocks over a network) [3].
• This makes a single, well-synchronised IST the present policy direction, and it would make any future split harder and costlier.

Related concepts

• Indian Standard Time keeping
• Chai bagaan time
• Dong Valley

Read more

• Indian Standard Time and the two-time-zones debate