World Clock - Check Time Across Time Zones

Time zones are regions of the globe that observe a uniform standard time for legal, commercial, and social purposes. Time zones tend to follow the boundaries of countries and their subdivisions because it is convenient for areas in close commercial or other communication to keep the same time.

Most of the time zones on land are offset from Coordinated Universal Time (UTC) by a whole number of hours (UTC−12:00 to UTC+14:00), but a few zones are offset by 30 or 45 minutes (e.g., Newfoundland Standard Time is UTC−03:30, Nepal Standard Time is UTC+05:45).

The History of Time Zones

Before the late 19th century, time was often determined locally through observations of the 🌞Sun, which meant that different places used slightly different local mean solar times. As railway and telecommunications networks expanded rapidly in the 19th century, the resulting confusion led to the introduction of standard time and time zones.

In 1884, the International Meridian Conference adopted a proposal that specified the Greenwich meridian as the prime meridian and Greenwich Mean Time (GMT) as the world's time standard. The standard time zones were formed by geometrically subdividing the Earth's spheroid into 24 lunes (wedge-shaped sections), each 15° of longitude in width.

Daylight Saving Time

Many regions and countries around the world observe daylight saving time (DST), also known as summer time. During DST, clocks are advanced by one hour at the beginning of spring and moved back in autumn to make better use of natural daylight. The practice aims to save energy and increase outdoor leisure time during the longer days of summer.

The implementation of DST varies across countries and regions, with different start and end dates. Some countries, particularly those near the equator where daylight hours are similar throughout the year, do not observe DST at all.