United States Naval Observatory

The United States Naval Observatory (USNO) is a scientific and military facility that produces geopositioning, navigation and timekeeping data for the United States Navy and the United States Department of Defense. Established in 1830 as the Depot of Charts and Instruments, it is one of the oldest scientific agencies in the United States, and remains a leading facility for astronomical and timing data.

Source: Wikipedia — United States Naval Observatory (CC BY-SA 4.0)