pituuspiirivyöhykkeeseen

A pituuspiirivyöhyke, often translated as a time zone, is a region that observes a uniform standard time for legal, commercial, and social purposes. The Earth is divided into 24 principal time zones, each spanning approximately 15 degrees of longitude. These zones are based on Coordinated Universal Time (UTC), which is the primary time standard by which the world regulates clocks and time.

The concept of time zones was established in the late 19th century to standardize timekeeping, particularly for railway transportation. Before this, each locality typically used its own solar time, leading to significant confusion and scheduling difficulties. The International Meridian Conference of 1884 adopted the Greenwich Meridian as the prime meridian (0 degrees longitude) and established the system of time zones based on it.

While theoretically, time zones follow lines of longitude, political and geographical boundaries often cause deviations. Countries or regions may adopt a single time zone for convenience, even if their territory spans multiple theoretical zones. Islands and remote areas also often adopt a time zone that aligns with a nearby mainland or a major trading partner.

There are also half-hour and even quarter-hour time zones in use in some parts of the world. These variations highlight the practical compromises made to balance the theoretical concept of longitudinal timekeeping with real-world administrative and social needs. The study and management of these time zones are crucial for global communication, travel, and commerce.