ajavöönde

Ajavöönde is a term originating from Estonian, translating to "time zone." It refers to a region of the globe that observes a uniform standard time for legal, commercial, and social purposes. These zones are established to approximate the solar time of the sun's highest point at noon. Historically, time zones were introduced to standardize railway schedules, which were previously based on local solar time and varied significantly from town to town. The concept gained widespread adoption in the late 19th and early 20th centuries.

The world is divided into 24 principal time zones, each theoretically spanning 15 degrees of longitude. However, political and geographical boundaries often cause these zones to deviate from strict longitudinal lines. Many countries observe daylight saving time, adjusting their clocks forward by an hour during warmer months to make better use of daylight. This practice, known as "suveajavöönde" (summer time zone) in Estonian, further complicates the standardized observation of time. The coordinated universal time (UTC) serves as the primary time standard by which all other time zones are defined, with differences usually expressed as a positive or negative offset from UTC.