Aikaskaala
Aikaskaala, or time scale, is a system for defining, maintaining, and comparing time across clocks and instruments. It provides a reference for timestamps, synchronization, and calculations in science, technology, and daily life. Time scales can be based on Earth’s rotation (dynamical, or solar time) or on atomic processes (physical time).
Major time scales include UT1, the time based on Earth's rotation, which reflects variations in rotation rate
Other scales include GPS Time, used by the Global Positioning System; it started as TAI and does
These scales are defined and maintained by international bodies such as the BIPM (Bureau International des