Assam's Tea Gardens Run an Hour Ahead of India
Chaibagaan time, the clock Assam's tea gardens have kept since the British period, is one hour ahead of Indian Standard Time and has no legal existence. In 2018 the laboratory that keeps Indian Standard Time proposed the country adopt it.
Put your watch forward one hour at the gate of an Assam tea garden and you will be on the right clock. The gardens of the Brahmaputra valley keep their own time, one hour ahead of Indian Standard Time, and have kept it since the British period. It is called chaibagaan time, or simply bagan time. It appears in no statute and on no railway timetable. And in 2018 the government laboratory that keeps Indian Standard Time published a peer-reviewed proposal that India adopt a second time zone. The time it proposed, to the minute, was the gardens'.
The usual telling has that backwards. Bagan time is not a quaint plantation habit the nation has patiently tolerated. It is a working measurement the nation's own measurement institute examined, agreed with, recommended, and then failed to adopt.
The garden day, and the two clocks it is written in
A tea garden in Assam works from nine in the morning to five in the afternoon on its own clock. On the clock the rest of India uses, that is eight to four. Those are the same eight hours described twice, and both descriptions are in circulation at once: the state's Labour Welfare Department, ordering shortened afternoons during a heat wave, described the normal garden schedule as 8 a.m. to 4 p.m., while the estate down the road will tell you the day starts at nine.
Nothing about the length of the day changes. The Plantations Labour Act caps an adult plantation worker at forty-eight hours a week, and the garden day is eight hours either way it is written. What changes is where those eight hours sit against the sun, and that is not a small matter when the work is finding two leaves and a bud by eye and getting them weighed before they wilt. Leaf cannot be plucked in the dark. A garden that started when Delhi started would send its pluckers out an hour after the light arrived and call them in an hour before it left.
The sun in Assam does not wait for the national meridian
The reason is geography, and it is blunt. India runs one time zone across a country wide enough for two. At the equinox the sun rises at Dong, at the country's eastern extreme, at 5:06 in the morning by Indian Standard Time, and at Ghuar Mota in the far west at 7:00. That is a spread of close to two hours, measured and published by the National Physical Laboratory in Current Science1, and every minute of it is absorbed by a single national clock.
Assam sits at the far end of that spread. Al Jazeera, reporting on the state's own attempt to change its clock, put the practical version in one line: in Assam it starts to get bright before 4am by the national clock in June, and is dark by 5pm in November5. A government office keeping national hours in Guwahati opens some five or six hours after first light in summer and closes after dark in winter. Arunachal Pradesh's chief minister Pema Khandu, pressing the same case in 2017, said his state is awake by four in the morning and that "several daylight hours are wasted as government offices open only at 10am and closes at 4pm"9.
By weight and measure, the garden clock overshoots the sun as well
A clock's offset from Greenwich stands for a line of longitude. The earth turns fifteen degrees an hour, so four minutes of clock buys one degree of sun. Indian Standard Time, at five and a half hours ahead, stands for a meridian near 82°33' east. A clock six and a half hours ahead, which is what the gardens keep, stands for 97°30' east.
Assam does not reach 97°30' east. The state's own biodiversity board puts its extent between 90 and 96 degrees east7. Run the arithmetic and the verdict is unflattering to both clocks. At Assam's eastern edge the country's clock sits about fifty-four minutes behind the sun, and the garden clock about six minutes ahead of it. At the far western edge the two are about equally wrong, some thirty minutes each in opposite directions.
What the estates run on is a round number rather than a solar one, adopted because a whole hour is what a clock face and a labour roster can carry, and everywhere in Assam it runs the sun a little early. The gap between the two widens the further east you go, and Assam's tea districts sit at the eastern end of the state, so on the ground the garden clock is the better reading nearly everywhere leaf is picked. Certified on both counts: the better of the two available measurements, and not itself a measurement.
The custodian of Indian Standard Time proposed the gardens' clock
In October 2018, fourteen scientists at the CSIR-National Physical Laboratory published a paper in Current Science proposing that India be put into two time zones. The laboratory is India's national measurement institute and, in its own words in that paper, the custodian of Indian Standard Time. It keeps, from a campus in New Delhi, the clock it was proposing to split.
Their scheme: IST-I at UTC+5:30 for the country west of 89°52' east, and IST-II at UTC+6:30 for everything east of it, which is Assam, Meghalaya, Nagaland, Arunachal Pradesh, Manipur, Mizoram, Tripura, and the Andaman and Nicobar Islands. The dividing line was chosen for a practical reason worth admiring: it falls on the West Bengal and Assam border, where only two railway stations, New Cooch Behar and Alipurduar, would need their timings managed by hand. The estimated saving in electricity, from the paper's own workings on population and daylight hours, came to twenty million kilowatt-hours a year.
And then, in the middle of the argument, the paper stops to note that the clock it is recommending already exists. Chaibagaan time, the authors write, meaning clocks set one hour ahead of Indian Standard Time and equal to the proposed IST-II, is already followed unofficially in Assam and has been since the British period. The Hindi edition of Down To Earth, covering the study, made the same connection8: the demand for a separate northeastern time is not theoretical, because the tea gardens have been running one since the plantations were laid out.
The planters who set that clock were working from daylight and a crop that has to be picked by hand and by eye, with no theory of the body behind it. They arrived at the same offset the national laboratory reached a century and a half later with sun graphs and census tables.
The one law that could have legalised it has never been used in Assam
Indian law anticipated this exact situation and then never got used. Section 3 of the Plantations Labour Act, 19512, the same act that made garden welfare compulsory, opens by fixing every reference to time in the act as Indian Standard Time. Then it adds a proviso: for any area where Indian Standard Time is not ordinarily observed, the state government may make rules specifying that area, defining the local mean time ordinarily observed there, and permitting that time to be kept in the plantations situated in it.
Assam has never made those rules. The Assam Plantations Labour Rules, 1956, as published by the state's own Commissionerate of Labour3, specify no such area and define no such time. Seventy years of a working legal mechanism, sitting unused, over the one industry it was plainly written for.
Note also what the proviso would have authorised. It permits "the local mean time ordinarily observed," which in Assam is thirty to fifty-four minutes ahead of Indian Standard Time depending where you stand. It does not permit a round hour. Even had the state used the provision, the clock it could legally have blessed would still not be the one hanging in the estate office.
The consequence is that every hour in the garden's own paperwork is a national hour. Section 23 requires each plantation to display a notice of the periods of work and forbids working outside it, and it lets an employer refuse a worker a day's work if that worker turns up more than half an hour after the fixed start. The grace the law allows is thirty minutes. The gap between the two clocks in daily use is sixty.
Proposed, litigated, refused, and now pointed the other way
The gardens' clock has been offered to the state twice and turned down both times. In January 2014 the chief minister, Tarun Gogoi, proposed that Assam simply adopt bagan time, moving state office hours to nine until four. The change was never made, and the state keeps Indian Standard Time. In March 2017 the Gauhati High Court dismissed a public interest litigation6 that had asked for a direction to the central government to create a separate northeastern time zone, the Union having told the court that a high-level committee under the science ministry had already looked at the question.
The case against is not empty, and it deserves stating. Dilip Ahuja, the scientist whose energy-saving work is most often cited in support of the change, argued for advancing Indian Standard Time by half an hour for the whole country rather than splitting it, and warned that two zones risked "major confusion in communications between train operators" on a network that crosses the boundary. That is a real objection about a real railway, raised by someone on the side of reform.
The national direction of travel since has been the reverse. On 15 January 2025 the Department of Consumer Affairs published draft rules under the Legal Metrology Act with the stated aim of "One Nation, One Time." By the government's own description of the draft4, the rules would mandate that legal, administrative and commercial activity synchronise to Indian Standard Time and would prohibit the use of alternative time references unless explicitly permitted, with carve-outs only for scientific, astronomical and navigational use by prior approval. That draft went out for comment until 14 February 2025, and what lands in the final rules is not yet on the record. Nobody drafting it had a tea garden in mind. It is aimed at power grids, banking networks and satellite navigation, where microseconds matter. But an unofficial clock kept by an industry employing hundreds of thousands of people is, on the face of the draft, an alternative time reference.
So the position stands like this. India's own keeper of the national clock has published, in a peer-reviewed journal, that the eastern states should run on UTC+6:30. The tea gardens have been running on UTC+6:30 without asking anyone. The statute that would let the state make that lawful has sat unused since 1956. And the newest rule on the table would forbid the practice rather than adopt it. Meanwhile the notice board at the garden gate is written in national hours, the clock in the garden office reads nine when that notice says eight, and the leaf comes in at the hour after sunrise the planters set it at.