A time zone is a region of the globe that observes a uniform standard time for legal, commercial, and social purposes. Time zones tend to follow the boundaries of countries and their subdivisions instead of strictly following longitude because it is convenient for areas in close commercial or other communication to keep the same time. The standard time within each zone is defined by an offset from Coordinated Universal Time (UTC), ranging from UTC−12:00 to UTC+14:00. Some zones include irregular minute offsets. Daylight saving time, where clocks are adjusted seasonally, is observed in many countries. Time zones have had a significant impact on economic activities and their development is closely tied to the evolution of transport and communication systems. Today, time zones are handled by various technologies, including operating systems and programming languages.
A time zone is an area which observes a uniform standard time pour legal, commercial et sociale purposes. Time zones tend to follow the boundaries between countries and their subdivisions instead of strictly following longitude, because it is convenient for areas in frequent communication to keep the same time.
Each time zone is defined by a standard offset from Coordinated Universal Time (UTC). The offsets range from UTC−12:00 à UTC+14:00, and are usually a whole number of hours, but a few zones are offset by an additional 30 or 45 minutes, such as in India et Nepal. Some areas in a time zone may use a different offset for part of the year, typically one hour ahead during spring et summer, a practice known as daylight saving time (DST).
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