# List of UTC timing centers

List of UTC timing centers is a list of over 70 recognized maintainers of atomic clocks around the world from which UTC is calculated. Below are links to some of the more notable time centers which contribute to the calculation of UTC. UTC is calculated by the International Bureau of Weights and Measures (BIPM) using weighted averages of the various times as reported by these 70+ listed timing centers. BIPM lists the time differences between the UTC timing centers in a monthly publication called Circular T, which contains the most up to date list of contributors to UTC.
List of institutes :
| Acronym | Full name | Country | City | Former acronym | CIPM MRA signatory | Start year | Stop year |
| AGGO | Argentinian-German Geodetic Observatory | Argentina | La Plata | TCC | | 2002 | |
| AOS | Astrogeodynamical Observatory, Space Research Centre P.A.S. | Poland | Borowiec | | | 1988 | |
| APL | Applied Physics Laboratory | United States of America | Laurel | | | 1978 | |
| AUS | National Measurement Institute | Australia | Sydney | | NMIA | 1973 | |
| BEV | Bundesamt für Eich- und Vermessungswesen | Austria | Wien | | BEV | 1975 | |
| BFKH | Government Office of Capital City of Budapest, Metrology and Technical Supervisory Department | Hungary | Budapest | MKEH | BFKH | 1974 | |
| BIM | Bulgarian Institute of Metrology | Bulgaria | Sofiya | NMC | BIM | 1991 | |
| BIRM | Beijing Institute of Radio Metrology and Measurement | P.R. China | Beijing | | | 1995 | |
| BOM | Bureau of Metrology of Macedonia | Macedonia | Skopje | | BOM | 2017 | |
| BSJ | Bureau of Standards Jamaica | Jamaica | Kingston | | BSJ | 2024 | |
| BY | Belarussian State Institute of Metrology | Belarus | Minsk | | BelGIM | 2007 | |
| CAO | Stazione Astronomica di Cagliari (Cagliari Astronomical Observatory) | Italy | Cagliari | | | 1982 | |
| CH | Federal Institute of Metrology (METAS) | Switzerland | Bern | | METAS | 1972 | |
| CNES | Centre National d'Etudes Spatiales | France | Toulouse | | | 2016 | |
| CNM | Centro Nacional de Metrologia | Mexico | Queretaro | | CENAM | 1996 | |
| CNMP | Centro Nacional de Metrología de Panamá (CENAMEP) | Panama | Panama | | CENAMAP AIP | 2003 | |
| DFM | Dansk Fundamental Metrologi (DFM A/S) | Denmark | Hørsholm | | DFM | 2022 | |
| DFNT | Laboratoire de Métrologie de la Direction Générale des Transmissions et de l'Informatique (DEF-NAT) | Tunisia | Tunis | | DEF-NAT | 2014 | |
| DLR | Deutsches Zentrum für Luft - und Raumfahrt (German Aerospace Centre) | Germany | Oberpfaffenhofen | | | 1996 | |
| DMDM | Directorate of Measures and Precious Metals | Serbia | Belgrade | | ZMDM | 1983 | |
| DTAG | Deutsche Telekom AG | Germany | Frankfurt/M | | | 1981 | |
| EIM | Hellenic Institute of Metrology | Greece | Thessaloniki | | EIM | 2007 | |
| ESA | European Space Agency | The Netherlands | Noordwijk | ESTC | ESA | 2012 | |
| HKO | Hong Kong Observatory | Hong Kong (China) | Hong Kong | | | 2004 | |
| IBM | Instituto Boliviano De Metrologia | Bolivia | La Paz | | IBMETRO | 2023 | |
| ICE | Laboratorio Costarricense de Metrologia | Costa Rica | San José | | LAMETRO-ICE | 2017 | |
| IDN | Standardization Agency of Indonesia | Indonesia | Jakarta | KIM | SNSU-BSN | 2008 | |
| IFAG | Bundesamt für Kartographie und Geodäsie (Federal Agency for Cartography and Geodesy) | Germany | Wettzell | | | 1988 | |
| IFZG | State Office for Metrology | Croatia | Zagreb | | DZM | 2024 | |
| IGNA | Instituto Geográfico Nacional | Argentina | Buenos Aires | | | 1969 | |
| IMBH | Institute of Metrology of Bosnia and Herzegovina | Bosnia and Herzegovina | Sarajevo | | IMBIH | 2015 | |
| INCP | Instituto Nacional de Calidad (INACAL) of Peru | Peru | Lima | | INACAL | 2016 | |
| INM | Instituto Nacional de Metrología of Colombia | Colombia | Bogota D.C. | | INM(CO) | 2017 | |
| INPL | National Physical Laboratory of Israel | Israel | Jerusalem | | INPL | 1988 | |
| INTI | Instituto Nacional de Tecnología Industrial | Argentina | Buenos Aires | | INTI | 2008 | |
| INXE | National Institute for Metrology, Quality and Technology (INMETRO) | Brazil | Rio de Janeiro | | INMETRO | 2012 | |
| IPQ | Instituto Portugues da Qualidade | Portugal | Caparica | | IPQ | 1995 | |
| IT | Istituto Nazionale di Ricerca Metrologica (INRIM) | Italy | Torino | IEN | INRIM | 1970 | |
| JATC | Joint Atomic Time Commission | P.R. China | Lintong | | | 1988 | |
| JV | Justervesenet | Norway | Kjeller | | JV | 2003 | |
| KEBS | Kenya Bureau of Standards | Kenya | Nairobi | | KEBS | 2012 | 2019 |
| KRIS | Korea Research Institute of Standards and Science (KRISS), | Rep. of Korea | Daejeon | KSRI | KRISS | 1988 | |
| KZ | Kazakhstan Institute of Standardization and Metrology | Kazakhstan | Astana | | KazStandard | 2008 | |
| LDS | University of Leeds | United Kingdom | Leeds | | | 1991 | 2009 |
| LRTE | Laboratório de Referência de Tempo e Espaço | Brazil | Sao Carlos | | | 2018 | |
| LT | Center for Physical Sciences and Technology (VMT/FTMC) | Lithuania | Vilnius | | FTMC | 2001 | |
| LUX | Bureau Luxembourgeois de Métrologie (ILNAS) | Luxembourg | Belvaux | | ILNAS | 2018 | |
| LV | Latvian National Metrology Centre | Latvia | Riga | | LATMB | 2007 | 2021 |
| MASM | Mongolian Agency for Standardization and Metrology | Mongolia | Ulaanbaatar | | MASM | 2013 | |
| MBM | Bureau of Metrology - Laboratory for time and frequency | Montenegro | Podgorica | | BMM | 2014 | |
| MIKE | VTT Technical Research Centre of Finland Ltd, Centre for Metrology | Finland | Espoo | | MIKES | 1978 | |
| MSL | Measurement Standards Laboratory | New Zealand | Lower Hutt | | MSL | 1984 | |
| MTC | MAKKAH Time Centre - King Abdulah Centre for Crescent Observations and Astronomy | Saudi Arabia | Makkah | | | 2012 | |
| NAO | National Astronomical Observatory | Japan | Mizusawa | NAOM | | 1969 | |
| NICT | National Institute of Information and Communications Technology | Japan | Tokyo | CRL | NICT | 1969 | |
| NIM | National Institute of Metrology | P.R. China | Beijing | | NIM | 1980 | |
| NIMB | National Institute of Metrology | Romania | Bucharest | | INM | 2002 | |
| NIMT | National Institute of Metrology (Thailand) | Thailand | Pathumthani | | NIMT | 2001 | |
| NIS | National Institute for Standards | Egypt | Cairo | | NIS | 1972 | |
| NIST | National Institute of Standards and Technology | United States of America | Boulder | NBS | NIST | 1969 | |
| NMIJ | National Metrology Institute of Japan | Japan | Tsukuba | NRLM | NMIJ AIST | 1980 | |
| NMLS | National Metrology Laboratory of SIRIM Berhad | Malaysia | Sepang | | NMIM | 2002 | |
| NPL | National Physical Laboratory | United Kingdom | Teddington | | NPL | 1969 | |
| NPLI | National Physical Laboratory | India | New-Delhi | | NPLI | 1988 | |
| NRC | National Research Council of Canada | Canada | Ottawa | | NRC | 1969 | |
| NRL | U.S. Naval Research Laboratory | United States of America | Washington DC | | | 2007 | |
| NSAI | National Standards Authority of Ireland's National Metrology Laboratory (NSAI NML) | Ireland | Dublin | | NSAI NML | 2020 | |
| NTSC | National Time Service Center of China | P.R. China | Lintong | CSAO | | 1980 | |
| ONBA | Observatorio Naval | Argentina | Buenos Aires | | | 1970 | |
| ONRJ | Observatório Nacional | Brazil | Rio de Janeiro | | ON/DSHO | 1972 | |
| OP | Observatoire de Paris/Laboratoire Temps Espace | France | Paris | LPTF,LNE-SYRTE | LNE-OP | 1968 | |
| ORB | Observatoire Royal de Belgique | Belgium | Bruxelles | | | 1972 | |
| PL | Consortium of laboratories in Poland | Poland | Warszawa | GUM | GUM | 1977 | |
| PTB | Physikalisch-Technische Bundesanstalt | Germany | Braunschweig | | PTB | 1968 | |
| ROA | Real Instituto y Observatorio de la Armada | Spain | San Fernando | OMSF | ROA | 1989 | |
| SASO | Saudi Standards, Metrology and Quality Organization | Saudi Arabia | Riyadh | | SASO-NMCC | 2013 | |
| SCL | Standards and Calibration Laboratory | Hong Kong (China) | Hong Kong | | SCL | 1996 | |
| SG | National Metrology Centre - Agency for Science, Technology and Research (A*STAR) | Singapore | Singapore | PSB | NMC, A*STAR | 1981 | |
| SIQ | Slovenian Institute of Quality and Metrology | Slovenia | Ljubljana | | MIRS/SIQ/Metrology | 2007 | |
| SL | Measurement Units, Standards and Services Department (MUSSD) | Sri Lanka | Colombo | | MUSSD | 2018 | |
| SMD | Metrology Division of the Quality and Safety Department - Scientific Metrology | Belgium | Bruxelles | | SMD | 2009 | |
| SMU | Slovenský Metrologický Ústav (Slovak Institute of Metrology) | Slovakia | Bratislava | | SMU | 1998 | |
| SP | Research Institutes of Sweden AB (RISE) | Sweden | Boras | | RISE | 1978 | |
| SU | Russian metrological institute of technical physics and radio engineering (FSUE VNIIFTRI") " | Russian Federation | Moskva | | VNIIFTRI | 1969 | |
| TL | Telecommunication Laboratories | Chinese Taipei | Chung-Li | | TL | 1972 | |
| TP | Institute of Photonics and Electronics, Czech Academy of Sciences (IPE/ASCR) | Czech Republic | Praha | | IPE/ASCR | 1968 | |
| TUG | Technische Universität | Austria | Graz | | | 1977 | 2000 |
| UA | National Scientific Centre Institute of Metrology"" | Ukraine | Kharkiv | | NSC IM | 2006 | |
| UAE | Emirates Metrology Institute (EMI/UAE) | The United Arab Emirates | Abu Dhabi | | EMI | 2017 | |
| UME | Ulusai Metroloji Enstitüsü, Marmara Research Centre, (National Metrology Institute) | Türkiye | Gebze-Kocaeli | | UME | 1994 | |
| USNO | U.S. Naval Observatory | United States of America | Washington DC | | | 1968 | |
| UTE | Administración Nacional de Usinas y Transmisiones | Uruguay | Montevideo | | UTE | 2023 | 2024 |
| UZ | Uzbek National Institute of Metrology of Uzstandard Agency | Uzbekistan | Tashkent | | UzNIM | 2023 | |
| VMI | Vietnam Metrology Institute | Vietnam | Ha Noi | | VMI-STAMEQ | 2008 | |
| VSL | VSL, Dutch Metrology Institute | The Netherlands | Delft | | VSL | 1973 | |
| ZA | National Metrology Institute of South Africa (NMISA) | South Africa | Pretoria | CSIR | NMISA | 1972 | |