UTC offset in the context of "UTC 8"

Central European Time (CET) is a standard time observed in Central as well as parts of Western and Southeast Europe, which is one hour ahead of Coordinated Universal Time (UTC). The time offset from UTC can be written as UTC+01:00. It covers most of continental Europe and it has been adopted by several African countries where it is known under various other names.

CET is also known as Middle European Time (MET, German: MEZ) and by colloquial names that reference major European cities such as Amsterdam Time, Berlin Time, Brussels Time, Budapest Time, Madrid Time, Paris Time, Stockholm Time, Rome Time, Prague time, Warsaw Time or Romance Standard Time (RST).

In modern usage, civil time refers to statutory time as designated by civilian authorities. Modern civil time is generally national standard time in a time zone at a fixed offset from Coordinated Universal Time (UTC), possibly adjusted by daylight saving time during part of the year. UTC is calculated by reference to atomic clocks and was adopted in 1972. Older systems use telescope observations.

In traditional astronomical usage, civil time was mean solar time reckoned from midnight. Before 1925, the astronomical time 00:00:00 meant noon, twelve hours after the civil time 00:00:00 which meant midnight. HM Nautical Almanac Office in the United Kingdom used Greenwich Mean Time (GMT) for both conventions, leading to ambiguity, whereas the Nautical Almanac Office at the United States Naval Observatory used GMT for the pre-1925 convention and Greenwich Civil Time (GCT) for the post-1924 convention until 1952. In 1928, the International Astronomical Union introduced the term Universal Time for GMT beginning at midnight.

UTC+08:00 is an identifier for a time offset from UTC of +08:00.

It is the most populous time zone in the world, as well as a possible candidate for ASEAN Common Time, mainly due to China's large population, with an estimated population of 1.4 billion people.

The time in China follows a single standard time offset of UTC+08:00, where Beijing is located, even though the country spans five geographical time zones. It is the largest sovereign nation in the world that officially observes only one time zone.

The nationwide standardized time is named Beijing Time (BJT; Chinese: 北京时间) domestically and China Standard Time (CST) internationally. Daylight saving time has not been observed since 1991.

ISO 8601 is an international standard covering the worldwide exchange and communication of date and time-related data. It is maintained by the International Organization for Standardization (ISO) and was first published in 1988, with updates in 1991, 2000, 2004, and 2019, and an amendment in 2022. The standard provides a well-defined, unambiguous method of representing calendar dates and times in worldwide communications, especially to avoid misinterpreting numeric dates and times when such data is transferred between countries with different conventions for writing numeric dates and times.

ISO 8601 applies to these representations and formats: dates, in the Gregorian calendar (including the proleptic Gregorian calendar); times, based on the 24-hour timekeeping system, with optional UTC offset; time intervals; and combinations thereof. The standard does not assign specific meaning to any element of the dates/times represented: the meaning of any element depends on the context of its use. Dates and times represented cannot use words that do not have a specified numerical meaning within the standard (thus excluding names of years in the Chinese calendar), or that do not use computer characters (excludes images or sounds).

Standard time is the synchronization of clocks within a geographical region to a single time standard, rather than a local mean time standard. The term is also used to contrast with daylight saving time, a period of the year when clocks are shifted ahead one hour, supposedly to make better use of daily sunlight from spring to fall. Applied globally in the 20th century, the geographical regions became time zones. The standard time in each time zone has come to be defined as an offset from Universal Time. A further offset is applied for part of the year in regions with daylight saving time. Generally, standard time agrees with the local mean time at some meridian that passes through the region, often near the centre of the region. Historically, standard time was established during the 19th century to aid weather forecasting and train travel.

The adoption of standard time, because of the inseparable correspondence between longitude and time, solidified the concept of halving the globe into the Eastern Hemisphere and the Western Hemisphere, with one Prime Meridian replacing the various prime meridians that had previously been used.

Africa, the world's second-largest and second-most populous continent, spans across six different time zone offsets from Coordinated Universal Time (UTC): UTC−01:00 to UTC+04:00. As Africa straddles the equator and tropics, there is little change in daylight hours throughout the year and as such daylight saving time is currently observed in only two countries, Morocco (year-round except Ramadan) and Egypt. However, it was previously observed in several other countries.

Before the wide adoption of standard time zones, local mean time was widely used in railway time for train timetables and telegraphic time for telegraphy. Local mean time is a solar time that corrects the variations of local apparent time by forming a uniform time scale at a specific longitude; for instance, Liberia observed UTC−0:44:30 instead of an approximate offset such as UTC−01:00. British Rhodesia (at the time administered by the private British South Africa Company) was the first area in Africa to adopt standard time, switching to UTC+02:30 on 1 August 1899 as the previous time standards proved problematic for the railway system. Other countries followed suit, and by 1912, most Portuguese, French and British territories had adopted a standard offset. Liberia was the last country in Africa to adopt a standard offset, doing so on 7 January 1972.

UTC+11:00 is an identifier for a time offset from UTC of +11:00. This time is used in: