Ajaarvestus

Ajaarvestus refers to the system of measuring and organizing time. It encompasses the methods used to define units of time, such as seconds, minutes, hours, days, weeks, months, and years, and the conventions for ordering these units into a coherent calendar. Throughout history, various cultures have developed different systems for tracking time, often influenced by astronomical observations like the cycles of the sun, moon, and stars.

The most widely adopted system today is the Gregorian calendar, a solar calendar that accurately approximates the Earth's orbital period around the sun. This calendar is crucial for regulating daily life, coordinating activities, and establishing historical records. Different cultures and regions may observe variations in their calendars or specific holidays, but the underlying principles of temporal measurement remain fundamental to societal organization. The scientific study of time measurement is known as chronometry.