His Majesty’s Nautical Almanac Office (HMNAO)

The UK government agency responsible for producing astronomical and navigational data for maritime and military use. 

His Majesty’s Nautical Almanac Office (HMNAO) is a division of the UK Hydrographic Office that provides essential astronomical and navigational information for seafarers, the military, and scientific institutions. Established in 1832, it produces publications such as the Nautical Almanac, which contains precise data on celestial bodies used for marine navigation. The office ensures that navigators have accurate information on the positions of the Sun, Moon, planets, and stars, which is critical for celestial navigation. HMNAO also collaborates with international organisations to maintain global standards for astronomical and navigational data. Its work supports not only maritime operations but also broader scientific research in astronomy and timekeeping.