Timezone converter
GMT to IST currently uses Greenwich Mean Time in Europe/London and India Time in Asia/Kolkata as the live reference pair, with a +5h 30m live gap. GMT and IST is the UK to India bridge, where mid-morning London still maps to a productive Bangalore afternoon. This is one of the cleaner intercontinental pairs because there is a real shared workday, not just an early-late handoff.
Offset math, DST behavior, and city coverage on both sides are refreshed from the live timezone dataset during the page revalidation window.
IST is ambiguous in this dataset, so the live converter uses Asia/Kolkata as the busiest reference zone while the city list below shows the wider label family.
From
Greenwich Mean Time
Europe/London · GMT+0 +00:00
Major markets in this grouping include London, Abidjan, Bamako, Dakar.
To
India Time
Asia/Kolkata · GMT+5:30 +05:30
Major markets in this grouping include Mumbai, Delhi, Bengaluru, Hyderabad.
Current gap
+5h 30m
GMT +00:00 vs IST +05:30
9-to-5 overlap
2.5h
GMT 9:00 AM previous day to 11:30 AM previous day
Representative countries
United Kingdom, Ivory Coast, and Mali / India, Israel, and Sri Lanka
Based on the busiest city and zone usage found in the current dataset.
GMT (London, +00:00) to IST (Mumbai, +05:30) is currently a +5h 30m conversion. Live coverage on the GMT side is anchored by London, Abidjan, Bamako, and Dakar; the IST side draws from Mumbai, Delhi, Bengaluru, and Hyderabad.
GMT and IST is the UK to India bridge, where mid-morning London still maps to a productive Bangalore afternoon. This is one of the cleaner intercontinental pairs because there is a real shared workday, not just an early-late handoff.
GMT means Greenwich, UK winter civil time, Iceland, Atlantic islands, and West African zero-offset countries; watch UK bank holidays, Irish public holidays, and West African national calendars. IST is grounded here by India, Israel, and Sri Lanka. The curated side is where most same-offset duplication risk is removed, because it names the civil calendar and operating context users actually mean.
This pair runs between Europe or Africa and Asia or the Pacific. With +5h 30m between them, the late European morning often catches the early Asian evening, which is the practical window for cross-region operations and travel planning.
GMT follows seasonal clock changes through Europe/London, while IST stays on a fixed offset year-round. That asymmetry is the real differentiator on this page: the gap widens or narrows by an hour twice a year, so calendar invites scheduled in one season often look wrong in the other.
GMT and IST sit 5h 30m apart, with about 2.5h of shared 9-to-5 time. That is enough room for one daily standup plus one focused working session, which is what most cross-region teams actually use this overlap for.
Reference zone, current offsets, country and city anchors, overlap math, and date-shift answers for GMT to IST.
Reference pair
Europe/London -> Asia/Kolkata
Live offsets
GMT +00:00 vs IST +05:30
Meaning split
Greenwich Mean Time / India Time
Country anchors
United Kingdom, Ivory Coast, and Mali -> India, Israel, and Sri Lanka
City anchors
London, Abidjan, Bamako, Dakar -> Mumbai, Delhi, Bengaluru, Hyderabad
Workday overlap
2.5h window: GMT 9:00 AM previous day-11:30 AM previous day
Morning answer
9 AM GMT = 2:30 PM IST, same day
Evening answer
6 PM GMT = 11:30 PM IST, same day
Same-offset labels can share the same hour while still landing in different countries, calendars, cities, and workday windows. These notes show the practical context behind this conversion.
GMT to IST is pinned to Europe/London -> Asia/Kolkata, with the shorthand labels shown as context. The city anchors are London, Abidjan, Bamako, Dakar on the GMT side and Mumbai, Delhi, Bengaluru, Hyderabad on the IST side, with +5h 30m between the live reference zones.
The 12 popular-hour answers include 11 same-day conversions, 1 next-day conversions, and 0 previous-day conversions. That distribution is what separates this page from a static offset chart.
Nearby labels sharing a current offset include UTC (From side), WEST (From side), WET (From side). They may match mathematically, but their country calendars, city anchors, and common search intent differ from this exact pair.
GMT: United Kingdom (GB); 863 mapped cities; capital London; English; GBP British pound | GMT: Ivory Coast (CI); 183 mapped cities; capital Yamoussoukro; French; XOF West African CFA franc | GMT: Mali (ML); 59 mapped cities; capital Bamako; French; XOF West African CFA franc | GMT: Senegal (SN); 70 mapped cities; capital Dakar; French; XOF West African CFA franc | GMT: Ghana (GH); 102 mapped cities; capital Accra; English; GHS Ghanaian cedi | IST: India (IN); 3776 mapped cities; capital New Delhi; English, Hindi, Tamil; INR Indian rupee | IST: Israel (IL); 108 mapped cities; capital Jerusalem; Arabic, Hebrew; ILS Israeli new shekel | IST: Sri Lanka (LK); 60 mapped cities; capital Sri Jayawardenepura Kotte; Sinhala, Tamil; LKR Sri Lankan rupee
Offset behavior, DST gap changes, local calendar evidence, and the day-shift pattern across the most common conversion hours.
GMT/IST is a regional or transcontinental offset gap: Europe/London currently reads +00:00, Asia/Kolkata reads +05:30, and the live delta is +5h 30m. This class decides whether the page behaves like a same-day planner or a handoff planner.
Europe/London changes from +00:00 (GMT+0) to +01:00 (GMT+1) on March 28, 2027 at about 2:00 AM.
No country holiday snapshot is attached to this exact pair yet, so the page leans on city anchors, IANA zones, offsets, and the live conversion table instead of pretending a local calendar exists.
Across the 12 popular-hour answers, this pair has 11 same-day answers, 1 next-day answers, 0 previous-day answers. That mix is specific to the current Europe/London -> Asia/Kolkata relationship and helps users see whether dates must be written explicitly in invites, travel plans, and release schedules.
Same-offset converter clusters can look identical if the page only shows a numeric offset. This audit states whether the route should be indexed, which canonical peer it follows when consolidated, and what pair-specific evidence keeps the page useful.
This pair remains indexable because the route has enough pair-specific context: Europe/London -> Asia/Kolkata, country anchors, city anchors, calendar notes, and day-shift examples.
GMT and IST are not currently a same-offset pair; the live delta is +5h 30m. Same-offset neighbors are still listed because users often confuse nearby abbreviations.
UTC (From side, +00:00), WEST (From side, +00:00), WET (From side, +00:00) The page keeps these labels visible so SGT/HKT/GST-style clusters do not blur into one generic offset page.
GMT/IST uses 11 same-day answers, 1 next-day answers, 0 previous-day answers; 2.5h strict workday overlap; source zones Europe/London and Asia/Kolkata; country anchors United Kingdom, Ivory Coast, and Mali -> India, Israel, and Sri Lanka.
Common places, calendars, markets, languages, and operating contexts behindGMT and IST.
GMT
GMT is not just a country clock. In this dataset it spans London, Dublin, Reykjavik, West Africa, Atlantic islands, and reference-style public schedules. It is commonly used as a source label in broadcasts, aviation-adjacent notices, release notes, and public event listings, but software and contracts often prefer UTC or a precise IANA zone.
GMT
For UK-facing planning, GMT needs a seasonal caveat: Europe/London can display British Summer Time while a sender still casually writes GMT. That is why converter pages using GMT should keep the exact reference zone visible instead of pretending the three-letter label is always enough.
Same-offset conversions can still land in different public-holiday, language, currency, and city-anchor contexts. These rows use the country profile and holiday snapshots behind each side of the pair.
GMT
863 mapped city anchors; zones Europe/London.capital London; English; GBP British pound
Holiday snapshot: New Year's Day (Jan 1, Public) · 2 January (Jan 2, Public) · Saint Patrick's Day (Mar 17, Public) · Good Friday (Apr 3, Public) · Easter Monday (Apr 6, Public)
GMT
183 mapped city anchors; zones Africa/Abidjan.capital Yamoussoukro; French; XOF West African CFA franc
Holiday snapshot: No holiday snapshot attached for the current year.
GMT
59 mapped city anchors; zones Africa/Bamako.capital Bamako; French; XOF West African CFA franc
Holiday snapshot: No holiday snapshot attached for the current year.
GMT
70 mapped city anchors; zones Africa/Dakar.capital Dakar; French; XOF West African CFA franc
Holiday snapshot: No holiday snapshot attached for the current year.
GMT
102 mapped city anchors; zones Africa/Accra.capital Accra; English; GHS Ghanaian cedi
Holiday snapshot: New Year's Day (Jan 1, Public) · Constitution Day (Jan 7, Public) · Independence Day (Mar 6, Public) · Good Friday (Apr 3, Public) · Easter Monday (Apr 6, Public)
IST
3,776 mapped city anchors; zones Asia/Kolkata.capital New Delhi; English, Hindi, Tamil; INR Indian rupee
Holiday snapshot: Republic Day (Jan 26, Public) · Holi (Mar 4, Public) · Eid al-Fitr (Mar 21, Public) · Mahavir Jayanti (Mar 31, Public) · Good Friday (Apr 3, Public)
These are the labels most likely to be confused with either side of this conversion. A matching UTC offset does not mean the same country, calendar, market, source convention, or user intent.
GMT and UTC match on offset right now, but the page should not collapse them: they carry different city anchors, country calendars, currencies, holidays, and user intent.
GMT and BST are close enough to be confused in search, but they are not the same clock label and should be pinned to exact IANA zones.
GMT and WEST match on offset right now, but the page should not collapse them: they carry different city anchors, country calendars, currencies, holidays, and user intent.
GMT and WET match on offset right now, but the page should not collapse them: they carry different city anchors, country calendars, currencies, holidays, and user intent.
GMT and AZOST are close enough to be confused in search, but they are not the same clock label and should be pinned to exact IANA zones.
GMT and AZOT are close enough to be confused in search, but they are not the same clock label and should be pinned to exact IANA zones.
IST and IOT are close enough to be confused in search, but they are not the same clock label and should be pinned to exact IANA zones.
IST and AFT are close enough to be confused in search, but they are not the same clock label and should be pinned to exact IANA zones.
IST and BST are close enough to be confused in search, but they are not the same clock label and should be pinned to exact IANA zones.
IST and BTT are close enough to be confused in search, but they are not the same clock label and should be pinned to exact IANA zones.
IST and CCT are close enough to be confused in search, but they are not the same clock label and should be pinned to exact IANA zones.
IST and FSAT are close enough to be confused in search, but they are not the same clock label and should be pinned to exact IANA zones.
Abbreviations with the same UTC offset can still represent different countries, cities, currencies, languages, and civil-time histories. This roster keeps theGMT to IST page grounded in those concrete places.
GMT: United Kingdom (GB); 863 mapped cities; zones Europe/London; city anchors London (Europe/London, pop 8,961,989), Birmingham (Europe/London, pop 1,157,603), Glasgow (Europe/London, pop 626,410), Manchester (Europe/London, pop 568,996); official United Kingdom of Great Britain and Northern Ireland; capital London; region Europe; subregion Northern Europe; population 69,281,437; area 244,376 km2; languages English; currency GBP British pound.
GMT: Ivory Coast (CI); 183 mapped cities; zones Africa/Abidjan; city anchors Abidjan (Africa/Abidjan, pop 6,321,017), Abobo (Africa/Abidjan, pop 1,340,083), Bouaké (Africa/Abidjan, pop 832,371), Korhogo (Africa/Abidjan, pop 440,926); official Republic of Côte d'Ivoire; capital Yamoussoukro; region Africa; subregion Western Africa; population 31,719,275; area 322,463 km2; languages French; currency XOF West African CFA franc.
GMT: Mali (ML); 59 mapped cities; zones Africa/Bamako; city anchors Bamako (Africa/Bamako, pop 4,227,569), Sikasso (Africa/Bamako, pop 349,324), Koutiala (Africa/Bamako, pop 218,031), Ségou (Africa/Bamako, pop 205,787); official Republic of Mali; capital Bamako; region Africa; subregion Western Africa; population 22,395,489; area 1,240,192 km2; languages French; currency XOF West African CFA franc.
GMT: Senegal (SN); 70 mapped cities; zones Africa/Dakar; city anchors Dakar (Africa/Dakar, pop 2,646,503), Touba (Africa/Dakar, pop 1,120,824), Pikine (Africa/Dakar, pop 874,062), Guédiawaye (Africa/Dakar, pop 329,659); official Republic of Senegal; capital Dakar; region Africa; subregion Western Africa; population 18,593,258; area 196,722 km2; languages French; currency XOF West African CFA franc.
GMT: Ghana (GH); 102 mapped cities; zones Africa/Accra; city anchors Kumasi (Africa/Accra, pop 2,544,530), Accra (Africa/Accra, pop 1,963,264), Tamale (Africa/Accra, pop 464,316), Takoradi (Africa/Accra, pop 389,114); official Republic of Ghana; capital Accra; region Africa; subregion Western Africa; population 33,742,380; area 238,533 km2; languages English; currency GHS Ghanaian cedi.
IST: India (IN); 3776 mapped cities; zones Asia/Kolkata; city anchors Mumbai (Asia/Kolkata, pop 12,691,836), Delhi (Asia/Kolkata, pop 11,034,555), Bengaluru (Asia/Kolkata, pop 8,495,492), Hyderabad (Asia/Kolkata, pop 6,993,262); official Republic of India; capital New Delhi; region Asia; subregion Southern Asia; population 1,417,492,000; area 3,287,263 km2; languages English, Hindi, Tamil; currency INR Indian rupee.
IST: Israel (IL); 108 mapped cities; zones Asia/Jerusalem; city anchors Jerusalem (Asia/Jerusalem, pop 971,800), Tel Aviv (Asia/Jerusalem, pop 432,892), West Jerusalem (Asia/Jerusalem, pop 400,000), Haifa (Asia/Jerusalem, pop 285,316); official State of Israel; capital Jerusalem; region Asia; subregion Western Asia; population 10,134,800; area 21,937 km2; languages Arabic, Hebrew; currency ILS Israeli new shekel.
IST: Sri Lanka (LK); 60 mapped cities; zones Asia/Colombo; city anchors Colombo (Asia/Colombo, pop 648,034), Dehiwala-Mount Lavinia (Asia/Colombo, pop 219,827), Maharagama (Asia/Colombo, pop 195,355), Jaffna (Asia/Colombo, pop 169,102); official Democratic Socialist Republic of Sri Lanka; capital Sri Jayawardenepura Kotte; region Asia; subregion Southern Asia; population 21,763,170; area 65,610 km2; languages Sinhala, Tamil; currency LKR Sri Lankan rupee.
Same-offset converter pages can look deceptively alike. These records pin the page to the exact abbreviations, IANA zones, countries, and city anchors behind GMT and IST.
GMT (gmt) is not marked ambiguous in the abbreviation catalog. Meaning records: Greenwich Mean Time at UTC+00:00; listed zones Africa/Abidjan; Africa/Bamako; Africa/Bissau; Africa/Conakry; Africa/Dakar; America/Danmarkshavn; Africa/Freetown; Atlantic/St Helena; Africa/Accra; Africa/Lome; Africa/Monrovia; Africa/Nouakchott; source label Greenwich Mean Time - Abidjan, Abobo, Bouaké, Korhogo.
GMT currently maps to 8 country footprints in the converter dataset: United Kingdom (GB), Ivory Coast (CI), Mali (ML), Senegal (SN), Ghana (GH), Burkina Faso (BF), Togo (TG), Guinea (GN). The footprint spans 8 IANA zones across 10 city anchors.
GMT city anchors in this indexed page family: London [london-GB, GB, Europe/London, pop 8,961,989]; Abidjan [abidjan-CI, CI, Africa/Abidjan, pop 6,321,017]; Bamako [bamako-ML, ML, Africa/Bamako, pop 4,227,569]; Dakar [dakar-SN, SN, Africa/Dakar, pop 2,646,503]; Kumasi [kumasi-GH, GH, Africa/Accra, pop 2,544,530]; Ouagadougou [ouagadougou-BF, BF, Africa/Ouagadougou, pop 2,415,266]; Lomé [lome-TG, TG, Africa/Lome, pop 2,188,376]; Accra [accra-GH, GH, Africa/Accra, pop 1,963,264]; Conakry [conakry-GN, GN, Africa/Conakry, pop 1,928,389]; Camayenne [camayenne-GN, GN, Africa/Conakry, pop 1,871,242].
GMT: United Kingdom (GB); 863 mapped cities; zones Europe/London; city anchors London (Europe/London, pop 8,961,989), Birmingham (Europe/London, pop 1,157,603), Glasgow (Europe/London, pop 626,410), Manchester (Europe/London, pop 568,996); official United Kingdom of Great Britain and Northern Ireland; capital London; region Europe; subregion Northern Europe; population 69,281,437; area 244,376 km2; languages English; currency GBP British pound. GMT: Ivory Coast (CI); 183 mapped cities; zones Africa/Abidjan; city anchors Abidjan (Africa/Abidjan, pop 6,321,017), Abobo (Africa/Abidjan, pop 1,340,083), Bouaké (Africa/Abidjan, pop 832,371), Korhogo (Africa/Abidjan, pop 440,926); official Republic of Côte d'Ivoire; capital Yamoussoukro; region Africa; subregion Western Africa; population 31,719,275; area 322,463 km2; languages French; currency XOF West African CFA franc. GMT: Mali (ML); 59 mapped cities; zones Africa/Bamako; city anchors Bamako (Africa/Bamako, pop 4,227,569), Sikasso (Africa/Bamako, pop 349,324), Koutiala (Africa/Bamako, pop 218,031), Ségou (Africa/Bamako, pop 205,787); official Republic of Mali; capital Bamako; region Africa; subregion Western Africa; population 22,395,489; area 1,240,192 km2; languages French; currency XOF West African CFA franc. GMT: Senegal (SN); 70 mapped cities; zones Africa/Dakar; city anchors Dakar (Africa/Dakar, pop 2,646,503), Touba (Africa/Dakar, pop 1,120,824), Pikine (Africa/Dakar, pop 874,062), Guédiawaye (Africa/Dakar, pop 329,659); official Republic of Senegal; capital Dakar; region Africa; subregion Western Africa; population 18,593,258; area 196,722 km2; languages French; currency XOF West African CFA franc. GMT: Ghana (GH); 102 mapped cities; zones Africa/Accra; city anchors Kumasi (Africa/Accra, pop 2,544,530), Accra (Africa/Accra, pop 1,963,264), Tamale (Africa/Accra, pop 464,316), Takoradi (Africa/Accra, pop 389,114); official Republic of Ghana; capital Accra; region Africa; subregion Western Africa; population 33,742,380; area 238,533 km2; languages English; currency GHS Ghanaian cedi.
IST (ist) is ambiguous in the abbreviation catalog. Meaning records: Israel Time at UTC+02:00; listed zones Asia/Jerusalem; source label Israel Time - Jerusalem, Tel Aviv, West Jerusalem, Haifa | India Time at UTC+05:30; listed zones Asia/Colombo; Asia/Kolkata; source label India Time - Colombo, Dehiwala-Mount Lavinia, Maharagama, Jaffna.
IST currently maps to 3 country footprints in the converter dataset: India (IN), Israel (IL), Sri Lanka (LK). The footprint spans 3 IANA zones across 10 city anchors.
IST city anchors in this indexed page family: Mumbai [mumbai-IN, IN, Asia/Kolkata, pop 12,691,836]; Delhi [delhi-IN, IN, Asia/Kolkata, pop 11,034,555]; Bengaluru [bengaluru-IN, IN, Asia/Kolkata, pop 8,495,492]; Hyderabad [hyderabad-IN, IN, Asia/Kolkata, pop 6,993,262]; Ahmedabad [ahmedabad-IN, IN, Asia/Kolkata, pop 6,357,693]; Chennai [chennai-IN, IN, Asia/Kolkata, pop 4,681,087]; Kolkata [kolkata-IN, IN, Asia/Kolkata, pop 4,631,392]; Surat [surat-IN, IN, Asia/Kolkata, pop 4,591,246]; Pune [pune-IN, IN, Asia/Kolkata, pop 3,124,458]; Jaipur [jaipur-IN, IN, Asia/Kolkata, pop 3,046,163].
IST: India (IN); 3776 mapped cities; zones Asia/Kolkata; city anchors Mumbai (Asia/Kolkata, pop 12,691,836), Delhi (Asia/Kolkata, pop 11,034,555), Bengaluru (Asia/Kolkata, pop 8,495,492), Hyderabad (Asia/Kolkata, pop 6,993,262); official Republic of India; capital New Delhi; region Asia; subregion Southern Asia; population 1,417,492,000; area 3,287,263 km2; languages English, Hindi, Tamil; currency INR Indian rupee. IST: Israel (IL); 108 mapped cities; zones Asia/Jerusalem; city anchors Jerusalem (Asia/Jerusalem, pop 971,800), Tel Aviv (Asia/Jerusalem, pop 432,892), West Jerusalem (Asia/Jerusalem, pop 400,000), Haifa (Asia/Jerusalem, pop 285,316); official State of Israel; capital Jerusalem; region Asia; subregion Western Asia; population 10,134,800; area 21,937 km2; languages Arabic, Hebrew; currency ILS Israeli new shekel. IST: Sri Lanka (LK); 60 mapped cities; zones Asia/Colombo; city anchors Colombo (Asia/Colombo, pop 648,034), Dehiwala-Mount Lavinia (Asia/Colombo, pop 219,827), Maharagama (Asia/Colombo, pop 195,355), Jaffna (Asia/Colombo, pop 169,102); official Democratic Socialist Republic of Sri Lanka; capital Sri Jayawardenepura Kotte; region Asia; subregion Southern Asia; population 21,763,170; area 65,610 km2; languages Sinhala, Tamil; currency LKR Sri Lankan rupee.
GMT started as Greenwich Mean Time and now lives a double life: a civil-time label still used by the UK and parts of West Africa in winter, and a casual synonym for UTC in broadcasting and public schedules. The two roles overlap most of the time, but precise work treats them as distinct. The busiest cities using GMT in the current catalog are London, Abidjan, Bamako, Dakar, and Kumasi. The lead live reference on this page is London (Europe/London), currently at +00:00 (GMT+0). Those cities are what give GMT its actual feel rather than the abstract offset. GMT has a local identity beyond its offset: Greenwich, UK winter civil time, Iceland, Atlantic islands, and West African zero-offset countries. Calendar signals such as UK bank holidays, Irish public holidays, West African national calendars, and Icelandic no-DST scheduling and operational signals such as broadcast timestamps, public event listings, shipping and aviation-adjacent notices, and release notes written for a general audience are why this abbreviation should not be flattened into a same-offset neighbor. GMT currently shows +00:00, but Europe/London observes seasonal clock changes — the next transition is around March 28, 2027. That means the offset on this page is a snapshot, not a permanent fact, so long-range scheduling should pin the underlying IANA zone instead of the abbreviation.
GMT is not heavily split in the current catalog, but the short label still hides the underlying IANA zone and any future policy change. The safe pattern is to write the abbreviation for humans and the zone for machines. GMT behaves as a civil label in several places and as a public shorthand for UTC elsewhere; systems should store UTC or an IANA zone when the distinction matters. Not the same as GST, HKT, or SGT: GMT is a zero-offset reference family, not a Gulf, Hong Kong, or Singapore civil calendar. Europe/London has an upcoming offset change on March 28, 2027. After that point, GMT on this page will read a different UTC offset until the next transition, so any saved timestamp should anchor to the IANA zone rather than the abbreviation. GMT remains common in public schedules and broadcasting, while software teams almost always prefer UTC or an explicit IANA zone. The two are not technically identical (GMT is a civil-time label observed in winter; UTC is a continuously-corrected atomic standard), but they are close enough that mixing them rarely breaks anything in practice.
GMT should not be blindly swapped with nearby labels. Adjacent references in the catalog: UTC (+00:00, Often compared as a zero-offset reference); BST (+06:00, Shares the greenwich time family); WEST (+00:00, Currently sits on the same UTC offset); WET (+00:00, Currently sits on the same UTC offset); AZOST (-01:00, Runs on a nearby UTC offset); AZOT (-01:00, Runs on a nearby UTC offset).
GMT has 1 meaning record, offset range UTC+00:00 to UTC+02:00, labels Greenwich Mean Time, and 22 country footprints across 22 IANA zones.
IST is reused across 2 different meanings in this dataset — India Time and Israel Time — which is why the short code alone is not enough to identify a place. Each meaning maps to its own IANA zone family and its own DST behavior, and they happen to share the same letters by historical accident more than by design. The busiest cities using IST in the current catalog are Mumbai, Delhi, Bengaluru, Hyderabad, and Ahmedabad. The lead live reference on this page is Mumbai (Asia/Kolkata), currently at +05:30 (GMT+5:30). Those cities are what give IST its actual feel rather than the abstract offset. Because IST spans UTC+02:00 to UTC+05:30 across the active meanings, software, calendars, and contracts should always pin a specific IANA zone such as Asia/Kolkata or a literal UTC offset. The short label is fine for headlines and chat; it is the wrong primitive for storing or scheduling timestamps.
IST appears with 2 distinct meanings in current data, splitting across UTC+02:00 to UTC+05:30. The short label looks tidy in writing but quietly hides which place you mean — pick a city, a country, or an IANA zone before it matters. Asia/Kolkata does not show an offset change in the next year, which makes IST predictable for short-term scheduling. Predictable is not the same as permanent — civil-time rules still get changed by governments on relatively short notice. For precise work, the safest equivalent of IST is the exact IANA zone used by your city or system. Asia/Kolkata sits at +05:30, ahead of UTC, which means daily logs in this zone reach a new calendar date before UTC does — a small detail that breaks date-based reporting if missed.
IST should not be blindly swapped with nearby labels. Adjacent references in the catalog: IOT (+06:00, Runs on a nearby UTC offset); AFT (+04:30, Runs on a nearby UTC offset); BST (+06:00, Runs on a nearby UTC offset); BTT (+06:00, Runs on a nearby UTC offset); CCT (+06:30, Runs on a nearby UTC offset); FSAT (+05:00, Runs on a nearby UTC offset).
IST has 2 meaning records, offset range UTC+02:00 to UTC+05:30, labels India Time, Israel Time, and 3 country footprints across 3 IANA zones.
GMT country anchor United Kingdom: The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in northwestern Europe, off the coast of the continental mainland. It comprises England, Scotland, Wales and Northern Ireland, with a population of over 69 million in 2024. The UK includes the island of Great Britain, the north-eastern part of the island of Ireland, and most of the smaller islands within the British Isles, covering 94,354 square miles (244,376 km2). It shares a land border with the Republic of Ireland and is surrounded by the Atlantic Ocean, the North Sea, the English Channel, the Celtic Sea and the Irish Sea, while maintaining sovereignty over the Crown Dependencies and the British Overseas Territories. The capital and largest city of England and the UK is London; Edinburgh, Cardiff and Belfast are the national capitals of Scotland, Wales and Northern Ireland. Source: Wikipedia.
IST country anchor India: India, officially the Republic of India, is a country in South Asia. It is the seventh-largest country by area; the most populous country since 2023; and, since its independence in 1947, the world's most populous democracy. Bounded by the Indian Ocean on the south, the Arabian Sea on the southwest, and the Bay of Bengal on the southeast, it shares land borders with Pakistan to the west; China, Nepal, and Bhutan to the north; and Bangladesh and Myanmar to the east. In the Indian Ocean, India is near Sri Lanka and the Maldives. Its Andaman and Nicobar Islands share a maritime border with Myanmar, Thailand, and Indonesia. Source: Wikipedia.
GMT is not just a country clock. In this dataset it spans London, Dublin, Reykjavik, West Africa, Atlantic islands, and reference-style public schedules. It is commonly used as a source label in broadcasts, aviation-adjacent notices, release notes, and public event listings, but software and contracts often prefer UTC or a precise IANA zone.
For UK-facing planning, GMT needs a seasonal caveat: Europe/London can display British Summer Time while a sender still casually writes GMT. That is why converter pages using GMT should keep the exact reference zone visible instead of pretending the three-letter label is always enough.
GMT/IST uses Europe/London -> Asia/Kolkata, offset delta +5h 30m, overlap 2.5h, route /convert/gmt/ist/, and live abbreviation readings GMT+0/GMT+5:30.
GMT coverage on this page is led by London, United Kingdom, Abidjan, Ivory Coast, Bamako, Mali, and Dakar, Senegal, with 2 more in the live dataset. That mix is what makes GMT feel anchored to European working-day rhythms in practice rather than just an abbreviation on a chart. Local signals include broadcast timestamps, public event listings, and shipping and aviation-adjacent notices.
IST coverage is led by Mumbai, India, Delhi, India, Bengaluru, India, and Hyderabad, India, with 2 more anchoring the wider label family. Combined with the GMT side, this conversion ends up describing Europe-to-Asia trade calls, manufacturing supply-chain coordination, and joint-venture standups.
Adjust the time. Digits roll like an odometer, and the swap button flips the zones.
Same day in both places.
Quick conversions for 9 AM, noon, 3 PM, 6 PM, and 9 PM based on today's local calendar.
| GMT | IST | Day relation |
|---|---|---|
| 9:00 AM | 2:30 PMThu, Nov 5 | same day |
| 12:00 PM | 5:30 PMThu, Nov 5 | same day |
| 3:00 PM | 8:30 PMThu, Nov 5 | same day |
| 6:00 PM | 11:30 PMThu, Nov 5 | same day |
| 9:00 PM | 2:30 AMFri, Nov 6 | next day |
Quick conversions for 9 AM, noon, 3 PM, 6 PM, and 9 PM based on today's local calendar.
| IST | GMT | Day relation |
|---|---|---|
| 9:00 AM | 3:30 AMThu, Nov 5 | same day |
| 12:00 PM | 6:30 AMThu, Nov 5 | same day |
| 3:00 PM | 9:30 AMThu, Nov 5 | same day |
| 6:00 PM | 12:30 PMThu, Nov 5 | same day |
| 9:00 PM | 3:30 PMThu, Nov 5 | same day |
GMT to IST ranges from GMT 9:00 AM (which lands at IST 2:30 PM) through GMT 9:00 PM (IST 2:30 AM). Across this +5h 30m gap, the middle of the GMT range usually lands in the IST afternoon — the reliable window for live calls between the two — while the early and late edges drift into IST morning or evening.
IST to GMT ranges from IST 9:00 AM (which lands at GMT 3:30 AM) through IST 9:00 PM (GMT 3:30 PM). Across this +5h 30m gap, the middle of the IST range usually lands in the GMT afternoon — the reliable window for live calls between the two — while the early and late edges drift into GMT morning or evening.
These direct answers are here for the exact-intent searches people actually use, like “10 AM GMT to IST” or “4 PM GMT in IST”.
8 AM GMT = 1:30 PM IST (13:30). On today's live calendar that lands on Thu, Nov 5 in IST, which means the answer is a same day conversion rather than a static offset lookup.
9 AM GMT = 2:30 PM IST (14:30). On today's live calendar that lands on Thu, Nov 5 in IST, which means the answer is a same day conversion rather than a static offset lookup.
10 AM GMT = 3:30 PM IST (15:30). On today's live calendar that lands on Thu, Nov 5 in IST, which means the answer is a same day conversion rather than a static offset lookup.
11 AM GMT = 4:30 PM IST (16:30). On today's live calendar that lands on Thu, Nov 5 in IST, which means the answer is a same day conversion rather than a static offset lookup.
12 PM GMT = 5:30 PM IST (17:30). On today's live calendar that lands on Thu, Nov 5 in IST, which means the answer is a same day conversion rather than a static offset lookup.
1 PM GMT = 6:30 PM IST (18:30). On today's live calendar that lands on Thu, Nov 5 in IST, which means the answer is a same day conversion rather than a static offset lookup.
2 PM GMT = 7:30 PM IST (19:30). On today's live calendar that lands on Thu, Nov 5 in IST, which means the answer is a same day conversion rather than a static offset lookup.
3 PM GMT = 8:30 PM IST (20:30). On today's live calendar that lands on Thu, Nov 5 in IST, which means the answer is a same day conversion rather than a static offset lookup.
4 PM GMT = 9:30 PM IST (21:30). On today's live calendar that lands on Thu, Nov 5 in IST, which means the answer is a same day conversion rather than a static offset lookup.
5 PM GMT = 10:30 PM IST (22:30). On today's live calendar that lands on Thu, Nov 5 in IST, which means the answer is a same day conversion rather than a static offset lookup.
6 PM GMT = 11:30 PM IST (23:30). On today's live calendar that lands on Thu, Nov 5 in IST, which means the answer is a same day conversion rather than a static offset lookup.
9 PM GMT = 2:30 AM IST (02:30). On today's live calendar that lands on Fri, Nov 6 in IST, which means the answer is a next day conversion rather than a static offset lookup.
The live gap is +5h 30m right now, based on Europe/London at +00:00 and Asia/Kolkata at +05:30. Europe/London changes offset on March 28, 2027, so the gap moves to +4h 30m after that transition.
The most usable workday block right now is about 2.5 hours: GMT 9:00 AM previous day to 11:30 AM previous day, which lines up with IST 2:30 PM previous day to 5:00 PM previous day.
Europe/London
GMT+0 · +00:00
Asia/Kolkata
GMT+5:30 · +05:30
These are the busiest live references selected from the abbreviation families on this page.
| GMT | IST |
|---|---|
| 00:00 | 05:30 |
| 01:00 | 06:30 |
| 02:00 | 07:30 |
| 03:00 | 08:30 |
| 04:00 | 09:30 |
| 05:00 | 10:30 |
| 06:00 | 11:30 |
| 07:00 | 12:30 |
| 08:00 | 13:30 |
| 09:00 | 14:30 |
| 10:00 | 15:30 |
| 11:00 | 16:30 |
| 12:00 | 17:30 |
| 13:00 | 18:30 |
| 14:00 | 19:30 |
| 15:00 | 20:30 |
| 16:00 | 21:30 |
| 17:00 | 22:30 |
| 18:00 | 23:30 |
| 19:00 | 00:30 |
| 20:00 | 01:30 |
| 21:00 | 02:30 |
| 22:00 | 03:30 |
| 23:00 | 04:30 |
Countries represented here include United Kingdom, Ivory Coast, and Mali.
Countries represented here include India, Israel, and Sri Lanka.
Once a conversion pair matters, people usually need a city page, compare page, or a broader browse surface next.
Interactive converter
Move from this static pair into the full timezone converter with more cities and abbreviations.
Compare city pairs
Use compare pages when the practical question is overlap, not just offset arithmetic.
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Browse city pages
Jump into the strongest city pages when you want location-specific timezone context.
