Free .NET developer tool

Windows ↔ IANA Time Zone Converter

Find the IANA (Olson) ID for a Windows time zone, or the Windows ID for `America/New_York` — the same CLDR mapping `TimeZoneInfo` uses, with live UTC offsets.

Runs entirely in your browser — nothing you paste is uploaded.

Search by Windows ID, IANA ID, city or offset

5 of 142 Windows time zones match. Mapping from Unicode CLDR (updated 2026-10-10).

Windows ID

Eastern Standard Time

(UTC-05:00) Eastern Time (US & Canada)

IANA ID (default)

America/New_York

All 10 IANA zones that map to Eastern Standard Time

Bahamas (BS): America/Nassau
Canada (CA): America/TorontoAmerica/Iqaluit
United States (US): America/New_YorkAmerica/DetroitAmerica/Indiana/PetersburgAmerica/Indiana/VincennesAmerica/Indiana/WinamacAmerica/Kentucky/MonticelloAmerica/Louisville

Windows ID

Eastern Standard Time (Mexico)

(UTC-05:00) Chetumal

IANA ID (default)

America/Cancun

Windows ID

AUS Eastern Standard Time

(UTC+10:00) Canberra, Melbourne, Sydney

IANA ID (default)

Australia/Sydney

All 2 IANA zones that map to AUS Eastern Standard Time

Australia (AU): Australia/SydneyAustralia/Melbourne

Windows ID

SA Eastern Standard Time

(UTC-03:00) Cayenne, Fortaleza

IANA ID (default)

America/Cayenne

All 11 IANA zones that map to SA Eastern Standard Time

Antarctica (AQ): Antarctica/RotheraAntarctica/Palmer
Brazil (BR): America/FortalezaAmerica/BelemAmerica/MaceioAmerica/RecifeAmerica/Santarem
Falkland Islands (FK): Atlantic/Stanley
French Guiana (GF): America/Cayenne
Suriname (SR): America/Paramaribo
Generic (Etc/) (ZZ): Etc/GMT+3

Windows ID

US Eastern Standard Time

(UTC-05:00) Indiana (East)

IANA ID (default)

America/Indianapolis

Current tzdb name: America/Indiana/Indianapolis

All 3 IANA zones that map to US Eastern Standard Time

United States (US): America/IndianapolisAmerica/Indiana/MarengoAmerica/Indiana/Vevay

Converting time zone IDs in .NET

Windows identifies zones by names like Eastern Standard Time; Linux, macOS, browsers, Java and most databases use IANA IDs like America/New_York. Since .NET 6 the conversion is built in, and FindSystemTimeZoneById accepts either form on any operating system:

TimeZoneInfo conversions

// .NET 6+: both directions, any OS (uses ICU + the CLDR table on this page)
if (TimeZoneInfo.TryConvertWindowsIdToIanaId("Eastern Standard Time", out string? iana))
    Console.WriteLine(iana);                        // America/New_York

// A specific region's zone rather than the default ("001") one
TimeZoneInfo.TryConvertWindowsIdToIanaId("Eastern Standard Time", "CA", out string? toronto);  // America/Toronto

if (TimeZoneInfo.TryConvertIanaIdToWindowsId("Europe/Berlin", out string? windows))
    Console.WriteLine(windows);                     // W. Europe Standard Time

// FindSystemTimeZoneById accepts either kind of ID on .NET 6+
TimeZoneInfo eastern = TimeZoneInfo.FindSystemTimeZoneById("America/New_York");

Getting local time instead of UTC

Cloud servers run in UTC, so DateTime.Now returns UTC there and a report that looked right on your machine is hours off in production. Keep values in UTC and convert only for display:

Local time from UTC

// Servers (and Azure App Service) usually run in UTC: DateTime.Now is UTC there.
DateTime utcNow = DateTime.UtcNow;
TimeZoneInfo zone = TimeZoneInfo.FindSystemTimeZoneById("Eastern Standard Time");
DateTime easternNow = TimeZoneInfo.ConvertTimeFromUtc(utcNow, zone);

bool isDst = zone.IsDaylightSavingTime(easternNow);
TimeSpan offset = zone.GetUtcOffset(utcNow);       // -04:00 in summer, -05:00 in winter

// Prefer DateTimeOffset when a value must remember its offset.
DateTimeOffset stamped = TimeZoneInfo.ConvertTime(DateTimeOffset.UtcNow, zone);

Complete Windows to IANA mapping (142 zones)

Windows ID	Default IANA ID	Windows display name
`Afghanistan Standard Time`	`Asia/Kabul`	(UTC+04:30) Kabul
`Alaskan Standard Time`	`America/Anchorage`	(UTC-09:00) Alaska
`Alberta Standard Time`	`America/Edmonton`	(UTC-07:00) Alberta
`Aleutian Standard Time`	`America/Adak`	(UTC-10:00) Aleutian Islands
`Altai Standard Time`	`Asia/Barnaul`	(UTC+07:00) Barnaul, Gorno-Altaysk
`Arab Standard Time`	`Asia/Riyadh`	(UTC+03:00) Kuwait, Riyadh
`Arabian Standard Time`	`Asia/Dubai`	(UTC+04:00) Abu Dhabi, Muscat
`Arabic Standard Time`	`Asia/Baghdad`	(UTC+03:00) Baghdad
`Argentina Standard Time`	`America/Buenos_Aires`	(UTC-03:00) City of Buenos Aires
`Astrakhan Standard Time`	`Europe/Astrakhan`	(UTC+04:00) Astrakhan, Ulyanovsk
`Atlantic Standard Time`	`America/Halifax`	(UTC-04:00) Atlantic Time (Canada)
`AUS Central Standard Time`	`Australia/Darwin`	(UTC+09:30) Darwin
`Aus Central W. Standard Time`	`Australia/Eucla`	(UTC+08:45) Eucla
`AUS Eastern Standard Time`	`Australia/Sydney`	(UTC+10:00) Canberra, Melbourne, Sydney
`Azerbaijan Standard Time`	`Asia/Baku`	(UTC+04:00) Baku
`Azores Standard Time`	`Atlantic/Azores`	(UTC-01:00) Azores
`Bahia Standard Time`	`America/Bahia`	(UTC-03:00) Salvador
`Bangladesh Standard Time`	`Asia/Dhaka`	(UTC+06:00) Dhaka
`Belarus Standard Time`	`Europe/Minsk`	(UTC+03:00) Minsk
`Bougainville Standard Time`	`Pacific/Bougainville`	(UTC+11:00) Bougainville Island
`British Columbia Standard Time`	`America/Vancouver`	(UTC-07:00) British Columbia
`Canada Central Standard Time`	`America/Regina`	(UTC-06:00) Saskatchewan
`Cape Verde Standard Time`	`Atlantic/Cape_Verde`	(UTC-01:00) Cabo Verde Is.
`Caucasus Standard Time`	`Asia/Yerevan`	(UTC+04:00) Yerevan
`Cen. Australia Standard Time`	`Australia/Adelaide`	(UTC+09:30) Adelaide
`Central America Standard Time`	`America/Guatemala`	(UTC-06:00) Central America
`Central Asia Standard Time`	`Asia/Bishkek`
`Central Brazilian Standard Time`	`America/Cuiaba`	(UTC-04:00) Cuiaba
`Central Europe Standard Time`	`Europe/Budapest`	(UTC+01:00) Belgrade, Bratislava, Budapest, Ljubljana, Prague
`Central European Standard Time`	`Europe/Warsaw`	(UTC+01:00) Sarajevo, Skopje, Warsaw, Zagreb
`Central Pacific Standard Time`	`Pacific/Guadalcanal`	(UTC+11:00) Solomon Is., New Caledonia
`Central Standard Time`	`America/Chicago`	(UTC-06:00) Central Time (US & Canada)
`Central Standard Time (Mexico)`	`America/Mexico_City`	(UTC-06:00) Guadalajara, Mexico City, Monterrey
`Chatham Islands Standard Time`	`Pacific/Chatham`	(UTC+12:45) Chatham Islands
`China Standard Time`	`Asia/Shanghai`	(UTC+08:00) Beijing, Chongqing, Hong Kong, Urumqi
`Cuba Standard Time`	`America/Havana`	(UTC-05:00) Havana
`Dateline Standard Time`	`Etc/GMT+12`	(UTC-12:00) International Date Line West
`E. Africa Standard Time`	`Africa/Nairobi`	(UTC+03:00) Nairobi
`E. Australia Standard Time`	`Australia/Brisbane`	(UTC+10:00) Brisbane
`E. Europe Standard Time`	`Europe/Chisinau`	(UTC+02:00) Chisinau
`E. South America Standard Time`	`America/Sao_Paulo`	(UTC-03:00) Brasilia
`Easter Island Standard Time`	`Pacific/Easter`	(UTC-06:00) Easter Island
`Eastern Standard Time`	`America/New_York`	(UTC-05:00) Eastern Time (US & Canada)
`Eastern Standard Time (Mexico)`	`America/Cancun`	(UTC-05:00) Chetumal
`Egypt Standard Time`	`Africa/Cairo`	(UTC+02:00) Cairo
`Ekaterinburg Standard Time`	`Asia/Yekaterinburg`	(UTC+05:00) Ekaterinburg
`Fiji Standard Time`	`Pacific/Fiji`	(UTC+12:00) Fiji
`FLE Standard Time`	`Europe/Kiev`	(UTC+02:00) Helsinki, Kyiv, Riga, Sofia, Tallinn, Vilnius
`Georgian Standard Time`	`Asia/Tbilisi`	(UTC+04:00) Tbilisi
`GMT Standard Time`	`Europe/London`	(UTC+00:00) Dublin, Edinburgh, Lisbon, London
`Greenland Standard Time`	`America/Godthab`	(UTC-03:00) Greenland
`Greenwich Standard Time`	`Atlantic/Reykjavik`	(UTC+00:00) Monrovia, Reykjavik
`GTB Standard Time`	`Europe/Bucharest`	(UTC+02:00) Athens, Bucharest
`Haiti Standard Time`	`America/Port-au-Prince`	(UTC-05:00) Haiti
`Hawaiian Standard Time`	`Pacific/Honolulu`	(UTC-10:00) Hawaii
`India Standard Time`	`Asia/Calcutta`	(UTC+05:30) Chennai, Kolkata, Mumbai, New Delhi
`Iran Standard Time`	`Asia/Tehran`	(UTC+03:30) Tehran
`Israel Standard Time`	`Asia/Jerusalem`	(UTC+02:00) Jerusalem
`Jordan Standard Time`	`Asia/Amman`	(UTC+02:00) Amman
`Kaliningrad Standard Time`	`Europe/Kaliningrad`	(UTC+02:00) Kaliningrad
`Korea Standard Time`	`Asia/Seoul`	(UTC+09:00) Seoul
`Libya Standard Time`	`Africa/Tripoli`	(UTC+02:00) Tripoli
`Line Islands Standard Time`	`Pacific/Kiritimati`	(UTC+14:00) Kiritimati Island
`Lord Howe Standard Time`	`Australia/Lord_Howe`	(UTC+10:30) Lord Howe Island
`Magadan Standard Time`	`Asia/Magadan`	(UTC+11:00) Magadan
`Magallanes Standard Time`	`America/Punta_Arenas`	(UTC-03:00) Punta Arenas
`Manitoba Standard Time`	`America/Winnipeg`	(UTC-05:00) Manitoba
`Marquesas Standard Time`	`Pacific/Marquesas`	(UTC-09:30) Marquesas Islands
`Mauritius Standard Time`	`Indian/Mauritius`	(UTC+04:00) Port Louis
`Middle East Standard Time`	`Asia/Beirut`	(UTC+02:00) Beirut
`Montevideo Standard Time`	`America/Montevideo`	(UTC-03:00) Montevideo
`Morocco Standard Time`	`Africa/Casablanca`	(UTC+01:00) Casablanca
`Mountain Standard Time`	`America/Denver`	(UTC-07:00) Mountain Time (US & Canada)
`Mountain Standard Time (Mexico)`	`America/Mazatlan`	(UTC-07:00) Chihuahua, La Paz, Mazatlan
`Myanmar Standard Time`	`Asia/Rangoon`	(UTC+06:30) Yangon (Rangoon)
`N. Central Asia Standard Time`	`Asia/Novosibirsk`	(UTC+07:00) Novosibirsk
`Namibia Standard Time`	`Africa/Windhoek`	(UTC+02:00) Windhoek
`Nepal Standard Time`	`Asia/Katmandu`	(UTC+05:45) Kathmandu
`New Zealand Standard Time`	`Pacific/Auckland`	(UTC+12:00) Auckland, Wellington
`Newfoundland Standard Time`	`America/St_Johns`	(UTC-03:30) Newfoundland
`Norfolk Standard Time`	`Pacific/Norfolk`	(UTC+11:00) Norfolk Island
`North Asia East Standard Time`	`Asia/Irkutsk`	(UTC+08:00) Irkutsk
`North Asia Standard Time`	`Asia/Krasnoyarsk`	(UTC+07:00) Krasnoyarsk
`North Korea Standard Time`	`Asia/Pyongyang`	(UTC+09:00) Pyongyang
`Omsk Standard Time`	`Asia/Omsk`	(UTC+06:00) Omsk
`Pacific SA Standard Time`	`America/Santiago`	(UTC-04:00) Santiago
`Pacific Standard Time`	`America/Los_Angeles`	(UTC-08:00) Pacific Time (US & Canada)
`Pacific Standard Time (Mexico)`	`America/Tijuana`	(UTC-08:00) Baja California
`Pakistan Standard Time`	`Asia/Karachi`	(UTC+05:00) Islamabad, Karachi
`Paraguay Standard Time`	`America/Asuncion`	(UTC-04:00) Asuncion
`Qyzylorda Standard Time`	`Asia/Qyzylorda`	(UTC+05:00) Qyzylorda
`Romance Standard Time`	`Europe/Paris`	(UTC+01:00) Brussels, Copenhagen, Madrid, Paris
`Russia Time Zone 10`	`Asia/Srednekolymsk`	(UTC+11:00) Chokurdakh
`Russia Time Zone 11`	`Asia/Kamchatka`	(UTC+12:00) Anadyr, Petropavlovsk-Kamchatsky
`Russia Time Zone 3`	`Europe/Samara`	(UTC+04:00) Izhevsk, Samara
`Russian Standard Time`	`Europe/Moscow`	(UTC+03:00) Moscow, St. Petersburg
`SA Eastern Standard Time`	`America/Cayenne`	(UTC-03:00) Cayenne, Fortaleza
`SA Pacific Standard Time`	`America/Bogota`	(UTC-05:00) Bogota, Lima, Quito, Rio Branco
`SA Western Standard Time`	`America/La_Paz`	(UTC-04:00) Georgetown, La Paz, Manaus, San Juan
`Saint Pierre Standard Time`	`America/Miquelon`	(UTC-03:00) Saint Pierre and Miquelon
`Sakhalin Standard Time`	`Asia/Sakhalin`	(UTC+11:00) Sakhalin
`Samoa Standard Time`	`Pacific/Apia`	(UTC+13:00) Samoa
`Sao Tome Standard Time`	`Africa/Sao_Tome`	(UTC+00:00) Sao Tome
`Saratov Standard Time`	`Europe/Saratov`	(UTC+04:00) Saratov
`SE Asia Standard Time`	`Asia/Bangkok`	(UTC+07:00) Bangkok, Hanoi, Jakarta
`Singapore Standard Time`	`Asia/Singapore`	(UTC+08:00) Kuala Lumpur, Singapore
`South Africa Standard Time`	`Africa/Johannesburg`	(UTC+02:00) Harare, Pretoria
`South Sudan Standard Time`	`Africa/Juba`	(UTC+02:00) Juba
`Sri Lanka Standard Time`	`Asia/Colombo`	(UTC+05:30) Sri Jayawardenepura
`Sudan Standard Time`	`Africa/Khartoum`	(UTC+02:00) Khartoum
`Syria Standard Time`	`Asia/Damascus`	(UTC+02:00) Damascus
`Taipei Standard Time`	`Asia/Taipei`	(UTC+08:00) Taipei
`Tasmania Standard Time`	`Australia/Hobart`	(UTC+10:00) Hobart
`Tocantins Standard Time`	`America/Araguaina`	(UTC-03:00) Araguaina
`Tokyo Standard Time`	`Asia/Tokyo`	(UTC+09:00) Osaka, Sapporo, Tokyo
`Tomsk Standard Time`	`Asia/Tomsk`	(UTC+07:00) Tomsk
`Tonga Standard Time`	`Pacific/Tongatapu`	(UTC+13:00) Nuku'alofa
`Transbaikal Standard Time`	`Asia/Chita`	(UTC+09:00) Chita
`Turkey Standard Time`	`Europe/Istanbul`	(UTC+03:00) Istanbul
`Turks And Caicos Standard Time`	`America/Grand_Turk`	(UTC-05:00) Turks and Caicos
`Ulaanbaatar Standard Time`	`Asia/Ulaanbaatar`	(UTC+08:00) Ulaanbaatar
`US Eastern Standard Time`	`America/Indianapolis`	(UTC-05:00) Indiana (East)
`US Mountain Standard Time`	`America/Phoenix`	(UTC-07:00) Arizona
`UTC`	`Etc/UTC`	(UTC) Coordinated Universal Time
`UTC-02`	`Etc/GMT+2`	(UTC-02:00) Coordinated Universal Time-02
`UTC-08`	`Etc/GMT+8`	(UTC-08:00) Coordinated Universal Time-08
`UTC-09`	`Etc/GMT+9`	(UTC-09:00) Coordinated Universal Time-09
`UTC-11`	`Etc/GMT+11`	(UTC-11:00) Coordinated Universal Time-11
`UTC+12`	`Etc/GMT-12`	(UTC+12:00) Coordinated Universal Time+12
`UTC+13`	`Etc/GMT-13`	(UTC+13:00) Coordinated Universal Time+13
`Venezuela Standard Time`	`America/Caracas`	(UTC-04:00) Caracas
`Vladivostok Standard Time`	`Asia/Vladivostok`	(UTC+10:00) Vladivostok
`Volgograd Standard Time`	`Europe/Volgograd`	(UTC+04:00) Volgograd
`W. Australia Standard Time`	`Australia/Perth`	(UTC+08:00) Perth
`W. Central Africa Standard Time`	`Africa/Lagos`	(UTC+01:00) West Central Africa
`W. Europe Standard Time`	`Europe/Berlin`	(UTC+01:00) Amsterdam, Berlin, Bern, Rome, Stockholm, Vienna
`W. Mongolia Standard Time`	`Asia/Hovd`	(UTC+07:00) Hovd
`West Asia Standard Time`	`Asia/Tashkent`	(UTC+05:00) Ashgabat, Tashkent
`West Bank Standard Time`	`Asia/Hebron`	(UTC+02:00) Gaza, Hebron
`West Pacific Standard Time`	`Pacific/Port_Moresby`	(UTC+10:00) Guam, Port Moresby
`Yakutsk Standard Time`	`Asia/Yakutsk`	(UTC+09:00) Yakutsk
`Yukon Standard Time`	`America/Whitehorse`	(UTC-07:00) Yukon

Frequently asked questions

How do I convert a Windows time zone ID to IANA in .NET?

Since .NET 6, call TimeZoneInfo.TryConvertWindowsIdToIanaId("Eastern Standard Time", out var ianaId), which returns "America/New_York". An overload takes a region code to pick the IANA zone for a specific country. The reverse is TimeZoneInfo.TryConvertIanaIdToWindowsId. Both use ICU and the Unicode CLDR mapping, which is the table this tool shows.

Does FindSystemTimeZoneById accept IANA IDs on Windows?

Yes, since .NET 6 TimeZoneInfo.FindSystemTimeZoneById accepts either kind of ID on any operating system, converting through ICU when necessary. On .NET Framework, and on .NET Core before 6, Windows only understood Windows IDs and Linux only IANA IDs, which is why libraries such as TimeZoneConverter were needed.

Why does one Windows zone map to several IANA zones?

Windows groups regions that currently share the same offset and daylight saving rules, while the IANA database keeps a separate zone for every region whose history differs. So "Eastern Standard Time" covers America/New_York, America/Detroit, America/Toronto and more. CLDR names one of them as the default for territory 001, which is what the conversion API returns when no region is given.

How do I get local time instead of UTC on an Azure or Linux server?

Servers usually run in UTC, so DateTime.Now returns UTC time there. Store and compute in UTC, and convert for display with TimeZoneInfo.ConvertTimeFromUtc(DateTime.UtcNow, TimeZoneInfo.FindSystemTimeZoneById("America/New_York")), or use DateTimeOffset to keep the offset with the value. Never rely on the server’s local time zone.

Eastern Standard Time

America/New_York

Eastern Standard Time (Mexico)

America/Cancun

AUS Eastern Standard Time

Australia/Sydney

SA Eastern Standard Time

America/Cayenne

US Eastern Standard Time

America/Indianapolis

Converting time zone IDs in .NET

Getting local time instead of UTC

Complete Windows to IANA mapping (142 zones)

Frequently asked questions

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