Why India’s single time zone hits the northeast hardest
New Delhi sees the June solstice sun rise at 05:23 IST and set at 19:21. Nearly two solar hours separate Gujarat from Arunachal Pradesh, yet every clock in the country reads the same. The result is a chronic mismatch in the east: mornings start in darkness on the clock and evenings vanish early.
By the time an office opens at 09:30 IST in the northeast, the sun has been up for hours. By late afternoon, usable light is gone. The morning sun goes unused while the evening demands electric light. A second time zone aims to shift that light to the end of the day.
Could IST-I cut India’s electricity demand? The 2006 Planning Commission study
The Planning Commission examined a two-zone system in 2006. The study proposed IST (UTC+5:30) for the west and a new zone at UTC+6:00 for the east. The headline finding was energy: if the northeast started its working day one clock hour earlier, evening lighting demand would drop. The report put the potential saving at roughly 2.7 billion units of electricity per year.
The Commission stopped short of a formal recommendation. It called the idea worth further study. No legislation followed.
The 2018 CSIR-NPL blueprint for IST-I (UTC+6:00)
India’s official timekeeper, CSIR-NPL, released a detailed plan in 2018. It named two zones:
- IST (UTC+5:30): the existing zone for western and central India.
- IST-I (UTC+6:00): a new zone covering Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland, Sikkim, and Tripura.
The laboratory backed its case with solar data. It argued the eastern states lose usable evening light compared with the west. The proposal did not become law.
2021: the government says no
A Lok Sabha question in 2021 forced a written reply. The Ministry of Science and Technology stated no second-zone proposal was under active consideration. Two reasons were given: national unity and operational complexity. The reply said the single zone “serves the country’s administrative and economic integration” and that disruption to railways and banking would outweigh any marginal benefit.
As of 2026-2027, no bill is pending. The single-zone policy stands.
The case for two zones: energy, health, and regional fairness
Supporters make three arguments.
Energy. The 2006 Planning Commission estimate of 2.7 billion units annually remains the reference figure. CSIR-NPL later noted that LED adoption shrinks the saving but does not erase it.
Health and output. A 2018 National Institute of Advanced Studies paper linked the early-sunrise mismatch to “social jet lag.” Workers reported flagging concentration in late afternoon and more sleep disruption. Aligning clock time with solar time would shift work hours into daylight.
Regional development. The northeast’s official day begins at 09:30 IST, hours after sun-up in summer. That gap makes the region less attractive for daylight-dependent industries, including tea processing and tourism. A zone aligned to local solar time could narrow the disadvantage.
Why India still says no: unity, railways, and the risk of chaos
The counter-arguments are equally concrete.
National unity. A single standard time is a symbol of a single nation. The 2021 government reply cited this explicitly.
Railways. Indian Railways runs on IST. A second zone would demand dual timetables, dual station clocks, and reworked reservation systems. The cost of reconfiguring a network that already spans 29° of longitude is the single largest obstacle.
Confusion. India has no daylight saving time. Everyone knows the offset: UTC+5:30. Introducing UTC+6:00 for eight states would force travellers, broadcasters, and businesses to check which zone they are in. Missed meetings, missed flights, and scheduling errors would follow.
How IST-I would actually change a day in the northeast
If the CSIR-NPL plan were adopted, the practical shift would look like this:
| Scenario | Current IST | With IST-I (UTC+6:00) |
|---|---|---|
| School start, Guwahati | 08:00 IST | 08:00 IST-I (07:00 IST) |
| Office start, Guwahati | 09:30 IST | 09:30 IST-I (08:30 IST) |
Shifting the clock forward by one hour pushes sunrise even earlier on the new clock. The gain comes at the other end: sunset moves an hour later on the clock face, putting more light after the working day. In winter, though, mornings become darker on IST-I.
The proposed IANA zones were Asia/Guwahati and Asia/Aizawl. Neither was created. The global time zone database still lists one zone for India: Asia/Kolkata.
The strongest objection, answered
The claim: a second zone saves energy and improves life in the northeast.
The reply: the savings are real but modest. The 2006 estimate of 2.7 billion units represents about 1.5% of India’s total electricity consumption. The railway cost dwarfs it. Indian Railways runs thousands of passenger trains daily. Every timetable, station clock, and reservation system would need reworking. That cost is not justified by the energy saving alone.
The health and productivity arguments hold for the northeast, but they also apply in reverse to the west. A two-zone fix for the east offers no relief to the west, where winter evenings already lose light early. The proposal solves one mismatch while leaving the other untouched.