How is the "correct" time officially determined?
Quick Answer: The "correct" time is officially determined by International Atomic Time (TAI) and coordinated worldwide through Coordinated Universal Time (UTC). UTC is based on ultra-precise atomic clocks and adjusted occasionally with leap seconds to stay in sync with Earth's rotation.
Atomic clocks, which count extremely stable vibrations of atoms, provide the most accurate timekeeping. These clocks are maintained by national laboratories worldwide. Their data feed into the International Bureau of Weights and Measures (BIPM), which calculates TAI.
UTC is then derived from TAI but includes leap seconds to align with Earth's slightly irregular rotation. This combined approach ensures that official time stays precise for everyday use, navigation, science, and technology.