aikavyöhykkeille

Aikavyöhykkeille, or time zones, are regions that observe a uniform standard time for legal, commercial, and social purposes. These zones are defined by their offset from Coordinated Universal Time (UTC), the primary time standard by which the world regulates clocks and time. The Earth is divided into 24 principal time zones, each approximately 15 degrees of longitude wide, corresponding to one hour. However, political and geographical boundaries often cause these zones to deviate from strict longitudinal lines.

The concept of time zones arose in the late 19th century with the expansion of railways and telegraphy, which made it necessary to synchronize time across vast distances. Before the establishment of standardized time zones, each town or city often kept its own local solar time, leading to significant confusion. In 1884, an international conference in Washington D.C. established a global system of time zones based on the Prime Meridian, which passes through Greenwich, London.

Most time zones are designated by their offset from UTC, such as UTC+1 (Central European Time) or UTC-5 (Eastern Standard Time). Some regions observe Daylight Saving Time, where clocks are advanced by an hour during warmer months to make better use of daylight. This practice is not universally adopted and can lead to further complexity in international scheduling. The accurate implementation and understanding of time zones are crucial for global communication, transportation, and commerce.