Explore topic-wise fullforms in Time

INFO: Full form for HNR is Heure Normale Des Rocheuses in Time category
HNR also has other full forms in other categories mentioned below.

Australia uses three main time zones: Australian Western Standard Time (AWST; UTC+08:00), Australian Central Standard Time (ACST; UTC+09:30), and Australian Eastern Standard Time (AEST; UTC+10:00). Time is regulated by the individual state governments, some of which observe daylight saving time (DST). Australia's external territories observe different time zones.

Standard time was introduced in the 1890s when all of the Australian colonies adopted it. Before the switch to standard time zones, each local city or town was free to determine its local time, called local mean time. Now, Western Australia uses Western Standard Time; South Australia and the Northern Territory use Central Standard Time; while New South Wales, Queensland, Tasmania, Victoria, Jervis Bay Territory, and the Australian Capital Territory use Eastern Standard Time.

Daylight saving time (+1 hour) is used in states in the south and south-east—South Australia, New South Wales, Victoria, Tasmania, and the ACT. It is not currently used in Western Australia, the Northern Territory or Queensland.

Norfolk Island has NFT (UTC+11:00; 1 hour ahead of AEST) and during summer has NFDT (UTC+12:00; 1 hour ahead of AEDT).

Each state and territory of Australia determines whether or not to use daylight saving time (DST). However, during World War I and World War II all states and territories had daylight saving by federal law, under the defence power in section 51 of the constitution. In 1968, Tasmania was the first state since the war to adopt daylight saving. In 1971, New South Wales, Victoria, Queensland, South Australia, and the Australian Capital Territory also adopted daylight saving, while Western Australia and the Northern Territory did not. Queensland abandoned daylight saving in 1972. Queensland and Western Australia have observed daylight saving over the past 40 years from time to time on a trial basis.

New South Wales, the Australian Capital Territory, Victoria, Tasmania and South Australia observe DST every year. This has resulted in three time zones becoming five during the daylight-saving period. South Australia time becomes UTC+10:30, called Central Daylight Time (CDT), possibly with "Australia" prefixed (ACDT). The time in the southeastern states becomes UTC+11:00, using "Eastern" in the time zone name, Eastern Daylight Time (EDT), respectively Australia Eastern Daylight Time (AEDT).

Officially, the change to and from DST takes place at 02:00 local standard time (which is 03:00 DST) on the appropriate Sunday.

Of the states that observe DST, most began on the last Sunday in October, and ended on the last Sunday in March, until 2007. Tasmania, owing to its further southern latitude began DST earlier, on the first Sunday in October, and ended on the last Sunday in March.

In the 2007-08 season, Tasmania started on the first Sunday in October whilst the ACT, NSW, Vic and SA started in the last Sunday in October. As part of the transition to earlier daylight saving, those states and Tasmania all finished on the first Sunday in April. For subsequent years, DST in the south-eastern states and SA now starts on the first Sunday in October, finishing on the first Sunday in April the next year.

Western Australia was not affected by these changes to DST, being the only state in 2007-08 to observe daylight saving from the last Sunday in October to the last Sunday in March. However, since 2009, it is on Standard time all year round.

Queensland (AEST UTC+10:00), Northern Territory (ACST UTC+09:30) and Western Australia (AWST UTC+08:00) do not observe DST.

INFO: Full form for AKDT is Alaska Daylight Saving Time [utc - 0900] in Time category
AKDT also has other full forms in other categories mentioned below.

INFO: Full form for UZT is Uzbekistan Time [utc + 0500] in Time category
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INFO: Full form for UTC is Coordinated Universal Time (temps Universel Coordonn in Time category
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INFO: Full form for TUC is Incorrect Abbreviation for Temps Universel Coordonn in Time category
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INFO: Full form for MST is Mountain Standard Time [utc - 0700] in Time category
MST also has other full forms in other categories mentioned below.

Moscow Time (MSK, Russian: моско́вское вре́мя) is the time zone for the city of Moscow, Russia, and most of western Russia, including Saint Petersburg. It is the second-westernmost of the eleven time zones of Russia. It has been set to UTC+03:00 without DST since 26 October 2014; before that date it had been set to UTC+04:00 year-round on 27 March 2011.

Moscow Time is used to schedule trains, ships, etc. throughout Russia, but airplane travel is scheduled using local time. Times in Russia are often announced throughout the country on radio stations as Moscow Time, which is also registered in telegrams, etc. Descriptions of time zones in Russia are often based on Moscow Time rather than UTC. For example, Yakutsk (UTC+09:00) is said to be MSK+6 in Russia.

INFO: Full form for ST is Sixteen Thirty in Time category
ST also has other full forms in other categories mentioned below.

Standard time is the synchronization of clocks within a geographical region to a single time standard, rather than a local mean time standard. Generally, standard time agrees with the local mean time at some meridian that passes through the region, often near the center of the region. Historically, standard time was established during the 19th century to aid weather forecasting and train travel. 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.

The adoption of standard time, because of the inseparable correspondence between time and longitude, solidified the concept of halving the globe into an eastern and western hemisphere, with one prime meridian replacing the various prime meridians that had previously been used.

Sidereal time ( sy-DEER-ee-əl) is a timekeeping system that astronomers use to locate celestial objects. Using sidereal time, it is possible to easily point a telescope to the proper coordinates in the night sky. In short, sidereal time is a "time scale that is based on Earth's rate of rotation measured relative to the fixed stars".

Viewed from the same location, a star seen at one position in the sky will be seen at the same position on another night at the same sidereal time. This is similar to how the time kept by a sundial can be used to find the location of the Sun. Just as the Sun and Moon appear to rise in the east and set in the west due to the rotation of Earth, so do the stars. Both solar time and sidereal time make use of the regularity of Earth's rotation about its polar axis: solar time following the Sun while, roughly speaking, sidereal time follows the distant fixed stars on the celestial sphere.

More exactly, sidereal time is the angle, measured along the celestial equator, from the observer's meridian to the great circle that passes through the March equinox and both celestial poles, and is usually expressed in hours, minutes, and seconds. Common time on a typical clock measures a slightly longer cycle, accounting not only for Earth's axial rotation but also for Earth's orbit around the Sun.

A sidereal day is approximately 86164.0905 seconds (23 h 56 min 4.0905 s or 23.9344696 h).

(Seconds here follow the SI definition and are not to be confused with ephemeris second.)

The March equinox itself precesses slowly westward relative to the fixed stars, completing one revolution in about 25,800 years, so the misnamed sidereal day ("sidereal" is derived from the Latin sidus meaning "star") is 0.0084 seconds shorter than the stellar day, Earth's period of rotation relative to the fixed stars.The slightly longer "true" sidereal period is measured as the Earth Rotation Angle (ERA), formerly the stellar angle. An increase of 360° in the ERA is a full rotation of the Earth.

Because Earth orbits the Sun once a year, the sidereal time at any given place and time will gain about four minutes against local civil time, every 24 hours, until, after a year has passed, one additional sidereal "day" has elapsed compared to the number of solar days that have gone by.

INFO: Full form for UT is Universal Time (now Considered As Ut0) in Time category
UT also has other full forms in other categories mentioned below.

Central European Time (CET) is a standard time which is 1 hour ahead of Coordinated Universal Time (UTC).The time offset from UTC can be written as UTC+01:00.It is used in most parts of Europe and in a few North African countries.CET is also known as Middle European Time (MET, German: MEZ) and by colloquial names such as Amsterdam Time, Berlin Time, Brussels Time, Madrid Time, Paris Time, Rome Time, and Warsaw Time.

The 15th meridian east is the central axis for UTC+01:00 in the world system of time zones.

As of 2011, all member states of the European Union observe summer time (daylight saving time), from the last Sunday in March to the last Sunday in October.States within the CET area switch to Central European Summer Time (CEST, UTC+02:00) for the summer.

In Africa, UTC+01:00 is called West Africa Time (WAT), where it is used by several countries, year round.Algeria, Morocco, and Tunisia also refer to it as Central European Time.

The Eastern Time Zone (ET) is a time zone encompassing part or all of 23 states in the eastern part of the United States, parts of eastern Canada, the state of Quintana Roo in Mexico, Panama and Colombia, mainland Ecuador, Peru, and a small portion of westernmost Brazil in South America, along with certain Caribbean and Atlantic islands.

Places that use:

On the second Sunday in March, at 2:00 a.m. EST, clocks are advanced to 3:00 a.m. EDT leaving a one-hour "gap". On the first Sunday in November, at 2:00 a.m. EDT, clocks are moved back to 1:00 a.m. EST, thus "duplicating" one hour. Southern parts of the zone (Panama and the Caribbean) do not observe daylight saving time.