National standards organizations are responsible for designating a standard clock and establishing time check procedures. They use atomic clocks for precision. Organizations can synchronize their clocks with official time for daily operations, and adjustments in pendulum clocks involve calculations based on pendulum length.
The designation of a standard clock and the establishment of procedures to perform a time check on a daily basis is typically the responsibility of a national standards organization, such as the National Institute of Standards and Technology (NIST) in the United States. They use atomic clocks, which are extremely accurate, to keep official time and distribute it. The measurement of time has evolved from the observation of celestial bodies to the precision of atomic clocks. Time zones were created to help manage the differences in local solar times across geographic regions. For personal or organizational timekeeping, an entity may designate its own standard clock and establish procedures for daily time checks, usually by synchronizing with an official time source.
Moreover, the adjustment of pendulum-driven clocks for accuracy, such as the calculation needed when a clock gains 5.00 seconds per day, involves understanding the relationship between the pendulum's length and the timekeeping properties of the clock.