ajavöönditega

Ajavöönditega refers to the concept of time zones. Time zones are regions of the globe that observe a uniform standard time for legal, commercial, and social purposes. They are defined by their offset from Coordinated Universal Time (UTC), which is the primary time standard by which the world regulates clocks and time.

The Earth rotates 360 degrees in approximately 24 hours, meaning it rotates 15 degrees per hour. Theoretically, this leads to 24 distinct time zones, each 15 degrees wide. However, the actual boundaries of time zones are often adjusted for political and geographical convenience. They do not always follow straight lines of longitude. Instead, they often follow the borders of countries or administrative regions, leading to irregular shapes.

The system of time zones was largely established in the late 19th century with the advent of railroads and widespread telegraph communication. Before standardized time zones, each locality would often set its own time based on the sun's position, leading to significant confusion when travel or communication occurred between different towns.

Most countries have adopted a single time zone, while larger countries, like Russia, Canada, and the United States, span multiple time zones. Some regions also observe daylight saving time, where clocks are advanced by an hour during warmer months to make better use of daylight. The international date line, located roughly at 180 degrees longitude, marks the boundary where one calendar day ends and the next begins.