About World Time Map
- Over 200 cities are included on our interactive World Time Map, each represented on the map by a marker.
- Hover over the marker to see the name and current local time of that location, or click on the marker for more details.
- Select 'More info' to be taken to a separate page, where further information on the relevant timezones and daylight saving adjustments can be found.
Coordinated Universal Time (UTC)
UTC is the time standard by which the world regulates clocks and time. UTC was officially formalised in 1963 and replaced Greenwich Mean Time (GMT) as the global time standard. As a result of a gradual slowing of the Earth's rotation, the average day is a fraction of a second more than 24 hours, for this reason leap seconds are added periodically into UTC to compensate. Despite GMT no longer having a precise definition, the terms UTC and GMT are often used interchangeably, with GMT still in common use in the United Kingdom and other countries belonging to the Commonwealth.
A time zone is a region on Earth that has a uniform standard time. The planet is split into a number of time zones, with the vast majority of them expressed as positive or negative offsets from UTC. Most of these time zones are offset from UTC by a whole number of hours and fall between UTC-12 and UTC+14, whilst a few, such as India, Iran and Nepal, use half-hour or quarter-hour deviations.
History of time zones
A worldwide system of time zones was proposed in 1879 by Canadian Sir Sandford Fleming. At the international meridian conference of 1884 it was agreed that a universal day of 24 hours should be adopted, commencing at Greenwich midnight. By the turn of the century, whilst most of the time on Earth was in the form of standard time zones, few of these used an offset from GMT. It wasn't until 30 years later that most of the world's major countries had adopted hourly time zones that were offset from GMT and later UTC. Nepal was the last country to conform and adjust its time to an offset of UTC in 1986.
Daylight Saving Time
Daylight saving time is the practice of temporarily advancing the clocks during the lighter months so that evenings have more daylight. First implemented by Germany in 1916, most countries have used it at some stage since then. The hope was that by having lighter evenings, electricity usage would be reduced and activites that exploit sunlight after working hours would benefit. It became widely adopted in the 1970s, particularly in North America and Europe, as a result of the energy crisis. Today, although not used by the majority of the world's countries, it is still common in the western world.