Convert IST to UTC India Standard Time ↔ Coordinated Universal Time Free Online Secure
Type a time in IST and read it in UTC straight away. The offset is −5:30 h, the arithmetic wraps at midnight, and the answer says which day it lands on.
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Through the day — Convert IST to UTC (India Standard Time ↔ Coordinated Universal Time)
| IST | UTC |
|---|---|
| 00:00 | 18:30 |
| 03:00 | 21:30 |
| 06:00 | 00:30 |
| 09:00 | 03:30 |
| 12:00 | 06:30 |
| 15:00 | 09:30 |
| 18:00 | 12:30 |
| 21:00 | 15:30 |
Where these units come from
Until the middle of the nineteenth century every town kept its own noon, set by the sun overhead, and nobody minded that the next town was four minutes behind. Railways ended that: a timetable cannot be written for a hundred local noons. Britain put its railways on Greenwich time in 1847, and in 1884 the International Meridian Conference in Washington chose Greenwich as the prime meridian and sketched the twenty-four-hour scheme we still use. Greenwich Mean Time was the world's reference until 1972, when Coordinated Universal Time replaced it: UTC is kept by atomic clocks and tied back to the turning Earth by leap seconds. The abbreviations on this page name standard time — the winter setting — which is why each one is a fixed number of hours rather than something that drifts through the year.
Where you meet them
A time zone becomes real the moment two people in different places have to agree on one moment: a call between offices, a flight that lands before it took off, a market that opens while you are asleep, a deadline written in somebody else's afternoon. Server logs, train and flight schedules and anything stamped with a time are kept in UTC precisely so that the question can always be settled, no matter whose clock was on the wall.
Questions people ask
What about summer time?
The offsets here are standard-time offsets, the ones a zone keeps in winter. Where summer time is observed, the same places move one hour further on for part of the year and take a different name: Central European Time becomes Central European Summer Time, Eastern Standard Time becomes Eastern Daylight Time. The switching dates are not the same in every country, and the two hemispheres change in opposite months, so for a date inside a summer-time period add an hour to whichever side observes it.
Why isn't every difference a whole number of hours?
Because offsets are decided by governments, not by geometry. India is half an hour off the hour, at UTC+05:30; Nepal is three quarters, at UTC+05:45; the Chatham Islands are at UTC+12:45. Any of these can be changed by law, and several countries have moved their offset within living memory.
Is the answer exact?
Where both units are defined in terms of one another by whole numbers, yes — the page says so above the figure, and the only rounding is in how many digits are shown. Where the ratio has no finite decimal, the page shows twelve significant digits and says the relation is approximate rather than pretending otherwise.
Does anything I type leave my device?
No. The arithmetic runs in your browser; nothing is uploaded and there is no server to upload it to. Load the page once and it keeps working with the network switched off.
Writing an Indian time in UTC
The Republic Day parade begins at 10:30. A national entrance examination runs from 14:00 to 17:00. The flag-hoisting at the Red Fort on Independence Day is at 07:30. All of these are Indian Standard Time, and anyone who keeps a register, a flight plan or a server log in UTC must convert IST to UTC. Subtract five hours and thirty minutes: 10:30 IST is 05:00 UTC, 14:00 IST is 08:30 UTC, and 07:30 IST is 02:00 UTC. Any Indian time before 05:30 belongs to the previous UTC date, so 04:00 IST is 22:30 UTC the day before. India does not change its clocks, so the rule is the same in every month.
The page below gives the rule, lookup tables, a profile of each zone, an explanation of the half-hour offset and a series of examples from education, national days, sport and business. The calculation takes place in your browser, and nothing you type is sent to a server.
How to convert IST to UTC
Subtract 5:30
IST is UTC+5:30, so UTC is five and a half hours behind. Subtract 5 hours and 30 minutes from the Indian time each time you convert IST to UTC. If the answer is negative, add 24 hours and use the previous date. For example, 03:10 IST gives −2:20, which is 21:40 UTC on the previous day.
Eight pairs to remember
00:30 IST is 19:00 UTC the day before. 06:15 IST is 00:45 UTC. 09:00 IST is 03:30 UTC. 12:00 IST is 06:30 UTC. 15:45 IST is 10:15 UTC. 18:00 IST is 12:30 UTC. 21:30 IST is 16:00 UTC. 23:45 IST is 18:15 UTC. Only the first falls on the earlier date.
Mental arithmetic
Subtract six hours and give back thirty minutes. For 17:00 IST, 17 minus 6 is 11, plus thirty minutes is 11:30 UTC. It always works, because 5:30 is six hours less half an hour.
Indian time in institutions
One zone for the nation
National examinations, parades, public radio and television, exchanges and railways all run on IST, UTC+5:30. There is one zone, although the country stretches from Gujarat to Assam. Programmes are printed in Indian time with no other label.
How it looks to a foreigner
A reader outside India who sees “10:30” in a programme needs to know that it is not their own time. Without a careful convert IST to UTC they may think the parade begins at 10:30 on their own clock.
UTC, the destination of global records
What it is
UTC is the scale used by aviation, banks, meteorology and international databases. It has no summer time and depends on no country’s law. A moment described in UTC can therefore be compared directly with any other, from anywhere.
The standard form
A time written 2026-01-26T10:30:00+05:30 is 2026-01-26T05:00:00Z. The date library does the subtraction by reading the offset in the text.
Five and a half hours in practice
Working days on two dials
A 09:00 to 17:00 working day in Bangalore occupies 03:30 to 11:30 on the UTC dial. A London office open from 09:00 to 17:00 GMT occupies 14:30 to 22:30 on the Indian clock. The two days touch only in a window of two and a half hours, 09:00 to 11:30 UTC.
Messages and replies
An e-mail sent from India at 14:30 IST reaches London at 09:00 GMT, at the start of the British day, and can be answered before lunch. The same e-mail sent at 18:30 IST reaches London at 13:00 GMT, and the answer comes back only the next Indian morning.
By air to Europe
A flight from Mumbai to Frankfurt that leaves at 03:30 IST, which is 22:00 UTC the previous day, and lasts about eight hours lands at 06:00 UTC, which is 07:00 in Germany in winter. The ticket shows 03:30 and 07:00, so the journey looks like three and a half hours, though it takes eight.
National examinations
Start times
The large entrance examinations are held in morning and afternoon sessions. A session from 09:00 to 12:00 IST runs from 03:30 to 06:30 UTC, and one from 15:00 to 18:00 IST from 09:30 to 12:30 UTC. School-leaving examinations begin at 10:30 IST, which is 05:00 UTC.
Families abroad
Families following from Bucharest on EET note that 10:30 IST is 07:00 there. With a “convert IST to UTC” calculation done in advance, parents know when to expect the first news about the papers.
Republic Day and Independence Day
The parade on 26 January
The Republic Day parade begins in the morning at 10:30 IST, which is 05:00 UTC. For London, on GMT, it begins at 05:00, and for Bucharest at 07:00. Television coverage starts half an hour earlier.
The flag on 15 August
On 15 August the flag is raised and the prime minister speaks early in the morning, for instance at 07:30 IST, which is 02:00 UTC. London is on BST then, so it is 03:00, and Bucharest is on EEST, so it is 05:00. Whoever wants to watch live must get up in the night.
The great bathing festival
Rituals at dawn
At the large religious gatherings on the Ganges, the ritual bath takes place at dawn, about 05:00 IST, which is 23:30 UTC on the previous day. An online broadcast for Europe is therefore the evening before.
Arrival of the processions
The processions reach the river between 06:00 and 09:00 IST, which is 00:30 to 03:30 UTC. A viewer in London watching at 00:30 GMT sees the start of the Indian day in the middle of the night. A “convert IST to UTC” calculation that is off by an hour means a missed procession.
The snake-boat races of Kerala
The August contest
The best-known snake-boat race in Kerala takes place on a Saturday in August, in the middle of the day, around 14:00 IST, which is 08:30 UTC. In summer London reads 09:30 BST and Bucharest 11:30 EEST.
The day’s programme
Heats begin at about 11:00 IST, which is 05:30 UTC. Whoever reads a programme in UTC adds 5:30 for the local hour and subtracts 5:30 for the other direction.
Start-ups in Bangalore
Calls with European clients
Bangalore companies hold their calls with European clients between 14:30 and 17:30 IST, which is 09:00 to 12:00 UTC. For a client in London these fall in the morning; for one in Berlin they fall around midday in summer.
Handover at the end of the day
Engineers who hand over their work at 17:30 IST hand it over at 12:00 UTC, which is 12:00 GMT in winter. Colleagues in London receive the notes at noon and have the afternoon to answer. In summer, the same handover is at 13:00 BST.
Cinema and evening premieres
Screenings
Evening screenings start at 21:30 IST, which is 16:00 UTC. Major premieres take place at 19:00 IST, which is 13:30 UTC. Online broadcasts for the European diaspora therefore start in the middle of the afternoon.
Online releases
A release announced for “midnight” by Indian platforms is at 18:30 UTC on the previous day. Viewers in Britain see it in the evening, at 18:30 GMT.
Health tourism and remote consultations
Clinics for patients in Europe
Clinics in Kerala and Chennai offer video consultations for patients abroad. A consultation at 17:00 IST is at 11:30 UTC, which is 13:30 in Romania in winter. Patients in the United States follow it at 06:30 EST.
Prescriptions and dates
Prescriptions carry the local date. One issued at 00:20 IST on 5 March was issued at 18:50 UTC on 4 March. Doing the “convert IST to UTC” calculation with the date in view shows the exact day of issue.
Tea and spice auctions
Morning schedules
Tea auctions in Kolkata and Guwahati begin in the morning, at 10:00 IST, which is 04:30 UTC. Buyers in London who bid remotely are awake at 04:30 GMT.
Results
Prices are published in the afternoon, at about 15:00 IST, which is 09:30 UTC. A buyer who wants to trade the same day uses the window between 09:30 and 11:30 UTC.
Chess and the tournament clock
Rounds in the afternoon
Big chess events in India start their rounds at about 15:00 IST, which is 09:30 UTC. A game that lasts five hours finishes at 20:00 IST, or 14:30 UTC. Fans in Europe follow the final moves in the middle of the afternoon.
Rest days and deadlines
Registration for tournaments closes at set local times. A deadline at 18:00 IST is at 12:30 UTC. Players abroad should use the UTC figure to avoid being an hour or so late.
Asian zones, taken from the Indian clock
How many hours to subtract
From Indian time subtract 5:30 for UTC, 1:30 for Dubai and 0:30 for Pakistan; add 0:15 for Nepal, 0:30 for Bangladesh, 2:30 for China and Singapore and 3:30 for Japan.
One moment on five clocks
When it is 12:00 in Mumbai, UTC reads 06:30, Dubai 10:30, Dhaka 12:30 and Tokyo 15:30. A “convert IST to UTC” calculation is easy to check against such anchors.
Dated examples
January
On Tuesday 13 January, 15:30 IST is 10:00 UTC. There is no summer time, so subtract 5:30.
March
On Tuesday 24 March, 15:30 IST is still 10:00 UTC. India does not change its clock in March.
July
On Tuesday 14 July, 15:30 IST is 10:00 UTC. The figure is the same as in January, even though Central Europe is now at 12:00 CEST.
November
On Tuesday 10 November, 15:30 IST is 10:00 UTC. The figure is the same in every month.
The Mumbai marathon
A start before sunrise
The Mumbai marathon is run in January, with the start of the full race at about 05:30 IST, which is 00:00 UTC. The broadcast for London therefore begins at midnight GMT. Runners want to avoid the heat, but viewers in Europe have to stay up late or watch the recording.
The finish
Winners of the full race finish in about two hours and ten minutes, so at about 07:40 IST, which is 02:10 UTC. If you convert IST to UTC for each stage, you see at once what is happening on your own clock.
Pilgrimage queues in the south
Rites before sunrise
At the great temples of southern India, ceremonies begin before sunrise. A wake-up service at 03:00 IST is at 21:30 UTC on the previous day. Pilgrims who queue from the evening before may wait for dozens of hours.
Booking online
Access tickets go on sale at fixed times on Indian time. A sale that opens at 09:00 IST begins at 03:30 UTC. A pilgrim in Europe who wants a place must be online at 03:30 GMT, in the dead of night.
Neither zone changes its clock
Period by period
Because IST and UTC keep their clocks still, one figure covers the whole year: UTC runs 5 hours 30 minutes behind IST.
What to do about it
The same rule applies in every month: the same 5 hours 30 minutes shift. Nothing about the sum changes with the season when you convert IST to UTC.
Hour-by-hour conversion chart
IST to UTC, every hour
00:00 IST corresponds to 18:30 UTC (previous day). 01:00 IST corresponds to 19:30 UTC (previous day). 02:00 IST corresponds to 20:30 UTC (previous day). 03:00 IST corresponds to 21:30 UTC (previous day). 04:00 IST corresponds to 22:30 UTC (previous day). 05:00 IST corresponds to 23:30 UTC (previous day). 06:00 IST corresponds to 00:30 UTC. 07:00 IST corresponds to 01:30 UTC. 08:00 IST corresponds to 02:30 UTC. 09:00 IST corresponds to 03:30 UTC. 10:00 IST corresponds to 04:30 UTC. 11:00 IST corresponds to 05:30 UTC. 12:00 IST corresponds to 06:30 UTC. 13:00 IST corresponds to 07:30 UTC. 14:00 IST corresponds to 08:30 UTC. 15:00 IST corresponds to 09:30 UTC. 16:00 IST corresponds to 10:30 UTC. 17:00 IST corresponds to 11:30 UTC. 18:00 IST corresponds to 12:30 UTC. 19:00 IST corresponds to 13:30 UTC. 20:00 IST corresponds to 14:30 UTC. 21:00 IST corresponds to 15:30 UTC. 22:00 IST corresponds to 16:30 UTC. 23:00 IST corresponds to 17:30 UTC.
A short guide
Each entry converts one full hour from IST to UTC, flagging any change of date. If you only need to convert IST to UTC once, the form above is quicker; for many readings, keep this chart at hand. Watch the minutes: a thirty-minute difference means :00 and :30 swap places and the hour is adjusted accordingly.
Half-hour conversions
IST half-hours in UTC
00:30 IST corresponds to 19:00 UTC (previous day). 01:30 IST corresponds to 20:00 UTC (previous day). 02:30 IST corresponds to 21:00 UTC (previous day). 03:30 IST corresponds to 22:00 UTC (previous day). 04:30 IST corresponds to 23:00 UTC (previous day). 05:30 IST corresponds to 00:00 UTC. 06:30 IST corresponds to 01:00 UTC. 07:30 IST corresponds to 02:00 UTC. 08:30 IST corresponds to 03:00 UTC. 09:30 IST corresponds to 04:00 UTC. 10:30 IST corresponds to 05:00 UTC. 11:30 IST corresponds to 06:00 UTC. 12:30 IST corresponds to 07:00 UTC. 13:30 IST corresponds to 08:00 UTC. 14:30 IST corresponds to 09:00 UTC. 15:30 IST corresponds to 10:00 UTC. 16:30 IST corresponds to 11:00 UTC. 17:30 IST corresponds to 12:00 UTC. 18:30 IST corresponds to 13:00 UTC. 19:30 IST corresponds to 14:00 UTC. 20:30 IST corresponds to 15:00 UTC. 21:30 IST corresponds to 16:00 UTC. 22:30 IST corresponds to 17:00 UTC. 23:30 IST corresponds to 18:00 UTC.
What to remember
Half-hour starts are as easy to convert as whole hours. The rows below are the result of the same rule you use when you convert IST to UTC.
Odd times, converted
Ten IST times and their UTC equivalents
01:05 IST corresponds to 19:35 UTC (previous day). 03:20 IST corresponds to 21:50 UTC (previous day). 05:50 IST corresponds to 00:20 UTC. 07:35 IST corresponds to 02:05 UTC. 10:10 IST corresponds to 04:40 UTC. 13:25 IST corresponds to 07:55 UTC. 16:40 IST corresponds to 11:10 UTC. 19:55 IST corresponds to 14:25 UTC. 22:15 IST corresponds to 16:45 UTC. 23:05 IST corresponds to 17:35 UTC.
Observation
Real schedules are rarely on the hour, so here are ten with awkward minutes. The offset includes thirty minutes, so check the minutes as well as the hour in every answer.
Is it morning or night there?
IST hours and the day in UTC
06:00 IST corresponds to 00:30 UTC (night). 08:00 IST corresponds to 02:30 UTC (night). 10:00 IST corresponds to 04:30 UTC (night). 12:00 IST corresponds to 06:30 UTC (early morning). 14:00 IST corresponds to 08:30 UTC (morning). 16:00 IST corresponds to 10:30 UTC (morning). 18:00 IST corresponds to 12:30 UTC (around midday). 20:00 IST corresponds to 14:30 UTC (afternoon). 22:00 IST corresponds to 16:30 UTC (afternoon).
A practical use
The list pairs a IST hour with its UTC time and a plain word for the time of day. It tells you at once whether the person you call has had breakfast or gone to bed.
Before you convert IST to UTC: a short checklist
Preparation
Check the zone names
IST here is always India (UTC+5:30), never Ireland’s summer time or Israel’s standard time. A time ending in Z, or labelled Zulu, is already in UTC.
Use a 24-hour clock
The 24-hour clock avoids a.m. and p.m. slips, so rewrite 4:30 p.m. as 16:30 before anything else. For example, 09:15 IST becomes 03:45 UTC.
Then
The operation
Subtract 5 hours 30 minutes. If the result passes midnight, correct the date: readings before 05:30 fall on the previous date.
A second example
Try a later hour: 22:40 IST is 17:10 UTC.
Traps to avoid when you convert IST to UTC
Adding instead of subtracting
Because UTC runs behind IST, the result must be an earlier clock reading. A later one points to an addition.
Losing the date
Anything on the IST clock before 05:30 lands on the previous date. Keeping the original date produces a one-day error.
Hunting for a summer correction
Neither IST nor UTC changes its clock, so there is no summer correction to make. The same figure applies in every month.
Confusing the abbreviation
If a schedule says IST, make sure it comes from India: Israel and Ireland use those letters too, at other offsets. Zulu time and the letter Z mean the same as UTC.
Questions and answers
How far apart are IST and UTC?
5 hours 30 minutes, and UTC is behind IST.
How do I convert IST to UTC?
Subtract 5 hours 30 minutes from the IST time, then fix the date if the result passes midnight.
What is 21:45 IST in UTC?
16:15 UTC.
Do the seasons affect this conversion?
No. The relationship is the same all year.
Is my input stored or uploaded?
No. Nothing leaves the page.
Related conversions
See also Convert IST to WET, Convert IST to EET, Convert PST to UTC, Convert WET to UTC, Convert UTC to PST, Convert WET to IST, Convert EST to CST, Convert CET to EST, Convert GMT to PST. The opposite direction is Convert UTC to IST.
The short version: subtract 5 hours 30 minutes, check the date, and you can convert IST to UTC with confidence. No account is needed.