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India Runs a Continent on One Clock, and Everybody Knows It Doesn't Fit

Delhi Metro trains cover about 140,000 kilometres every day.

The Earth is roughly 40,000 km around. So the network drives the equivalent of three and a half times around the world, daily, on 4,508 train trips, using 343 trains and 2,368 coaches, across 374 kilometres of line and 271 stations.

In 2025 it carried 2.36 billion passenger journeys — an average of 6.46 million people a day. Its single-day record, set on 8 August 2025, was 8,187,674 passengers. Trains run at a two-minute headway, much of the network is driverless, and DMRC reports punctuality of about 99.9%.

None of this existed in 2002. The first section opened on 24 December that year.

The other Delhi number is less flattering and explains why the metro was necessary. The city has around 11.4 million registered motor vehicles — roughly two-thirds of them two-wheelers — which is more than Greater Mumbai, Chennai and Kolkata combined.

The clock: a two-minute headway at 99.9% punctuality is a system that depends absolutely on everybody agreeing what time it is. Which makes Delhi an interesting place to run one.

Indian Standard Time was fixed on 1 September 1947 at UTC+5:30, calculated from a single meridian at 82°30′ east. India spans about 2,900 kilometres east to west — wider than the contiguous United States, which uses four zones — and by solar logic would have three.

The consequence is that the sun rises roughly ninety minutes earlier at India's eastern edge than at its western one. In Assam in November, the sun can set around half past four in the afternoon while the working day continues.

Assam's tea gardens have quietly run an hour ahead of the rest of the country since the British era, on an unofficial standard known as Tea Garden Time. They still do. Parliament has been asked about a second time zone at least sixteen times since 2002.

So in one country: a metro that keeps 6.4 million people to the same minute, and a tea estate that has been an hour out for a century and never bothered to mention it.

Indian Standard Time is UTC+5:30, and it is calculated from a single line of longitude at 82°30′ east — a meridian that passes through the clock tower at Mirzapur, in Uttar Pradesh. It became the country's official time on 1 September 1947, two weeks after independence, replacing the colonial patchwork of Bombay, Calcutta and Madras times.

One clock, for everybody, as a matter of national cohesion.

The trouble is the map. India is roughly 2,900 kilometres across from west to east. Based on mean solar time it would have three time zones. The continental United States, which is wider, has four.

The consequence is that the sun comes up in Dong, the easternmost village, roughly an hour and a half before it comes up in the far west of Gujarat. In Assam in November and December, sunset can arrive at around half past four in the afternoon while the official working day continues. In summer the sun is up there before four in the morning, with nobody scheduled to do anything for hours.

So the northeast quietly built its own time zone and never asked.

Tea Garden Time — chai bagan time — was introduced by British tea companies in Assam to get more daylight working hours out of the day. It is set one hour ahead of IST. It is completely unofficial, it appears in no international time zone database, and it is still in daily use on the tea estates. Workers wake, work and sleep by a clock the country does not recognise.

The clock: the argument has never gone away. Members of both houses of parliament have asked the government whether India will adopt two time zones at least sixteen times since 2002.

In January 2014 the state of Assam simply declared it was moving its clocks forward an hour to bagan time. It had no legal effect — time is a federal matter — and nothing happened.

Then India's own official timekeeper weighed in. The CSIR National Physical Laboratory published a study in Current Science concluding that two zones are technically feasible, with a narrow demarcation line at the West Bengal–Assam border. An earlier CSIR study estimated a separate northeastern zone could save around 2.7 billion kilowatt-hours of electricity a year.

The counter-argument has always been the same: Indian Railways runs roughly 13,000 trains a day on a single clock, and nobody wants to be the person who splits it.

So India keeps one time zone — chosen for unity, kept for logistics — and a few million people in the tea gardens go on running an hour ahead of their own country.

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