"UTC+13:00 UTC+13:00 is an identifier for a +13 hour time offset from UTC. ""Principal cities: Nuku'alofa, Fakaofo ""Principal cities: Apia"" ""Principal cities: Auckland, Suva"" The Republic of Kiribati introduced a change for its eastern half on 1 January 1995, from time zones −11 and −10 to +13 and +14, to avoid having the country divided by the International Date Line. Tonga has been on UTC+13 for many years. Daylight saving time was used in the southern summer seasons from October 1999 to January 2002, and from November 2016 to January 2017 (written 2017). UTC+13 was used as a daylight time"
"Time, maintained by an ensemble of atomic clocks around the world. Universal Time (UT), a term introduced in 1928, initially represented mean time at Greenwich determined in the traditional way to accord with the originally defined universal day; from 1 January 1956 (as decided by the IAU at Dublin, 1955, at the initiative of William Markowitz) this ""raw"" form of UT was re-labelled UT0 and effectively superseded by refined forms UT1 (UT0 equalised for the effects of polar wandering) and UT2 (UT1 further equalised for annual seasonal variations in earth rotation rate). Historically GMT has been used with two different"
"for almost everyone else it started at midnight. To avoid confusion, the name Universal Time was introduced to denote GMT as counted from midnight. Astronomers preferred the old convention to simplify their observational data, so that each night was logged under a single calendar date. Today Universal Time usually refers to UTC or UT1. The term ""GMT"" is especially used by bodies connected with the United Kingdom, such as the BBC World Service, the Royal Navy, the Met Office and others particularly in Arab countries, such as the Middle East Broadcasting Centre and OSN. It is a term commonly used"
"Coordinated Universal Time Coordinated Universal Time (abbreviated to UTC) is the primary time standard by which the world regulates clocks and time. It is within about 1 second of mean solar time at 0° longitude, and is not adjusted for daylight saving time. In some countries where English is spoken, the term Greenwich Mean Time (GMT) is often used as a synonym for UTC. The first Coordinated Universal Time was informally adopted on 1 January 1960 and was first officially adopted as CCIR Recommendation 374, ""Standard-Frequency and Time-Signal Emissions"", in 1963, but the official abbreviation of UTC and the official"
"standard time zones, only some of which used an hourly offset from GMT. Many applied the time at a local astronomical observatory to an entire country, without any reference to GMT. It took many decades before all time on Earth was in the form of time zones referred to some ""standard offset"" from GMT/UTC. By 1929, most major countries had adopted hourly time zones. Nepal was the last country to adopt a standard offset, shifting slightly to UTC+5:45 in 1956. Today, all nations use standard time zones for secular purposes, but they do not all apply the concept as originally"
"1980s. The landowner, Greenwich Hospital, has been enhancing the Market since 2014 and due to complete in Spring 2016. Greenwich Mean Time (GMT) is a term originally referring to mean solar time at the Royal Observatory, Greenwich in Greenwich. It is commonly used in practice to refer to Coordinated Universal Time (UTC) when this is viewed as a time zone, especially by bodies connected with the United Kingdom, such as the BBC World Service, the Royal Navy, the Met Office and others, although strictly UTC is an atomic time scale which only approximates GMT with a tolerance of 0.9 second."
"GMT. This change was made permanent from 1946 by the ""Standard Time Act 1945"", at which the time at the 180°E meridian was made the basis for New Zealand Time. NZST remained half an hour ahead of NZMT, and the Chatham Islands 45 minutes ahead of NZST. In the late 1940s the atomic clock was developed and several laboratories began atomic time scales. A new time scale known as Coordinated Universal Time (UTC) was adopted internationally in 1972. This was based on the readings of atomic clocks, updated periodically in accordance with time variations in the Earth's rotation by the"
"UT1-UTC from the IERS, and apply corrections in software. Leap second A leap second is a one-second adjustment that is occasionally applied to civil time Coordinated Universal Time (UTC) to keep it close to the mean solar time at Greenwich, in spite of the Earth's rotation slowdown and irregularities. UTC was introduced on January 1, 1972, initially with a 10 second lag behind International Atomic Time (TAI). Since that date, 27 leap seconds have been inserted, the most recent on December 31, 2016 at 23:59:60 UTC, so in 2018, UTC lags behind TAI by an offset of 37 seconds. The"
"in the International Meridian Conference of 1884. Synchronisation of the chronometer on GMT did not affect shipboard time, which was still solar time. But this practice, combined with mariners from other nations drawing from Nevil Maskelyne's method of lunar distances based on observations at Greenwich, led to GMT being used worldwide as a standard time independent of location. Most time zones were based upon GMT, as an offset of a number of hours (and possibly half or quarter hours) ""ahead of GMT"" or ""behind GMT"". Greenwich Mean Time was adopted across the island of Great Britain by the Railway Clearing"
"1880, when Greenwich Mean Time was legally adopted throughout the island of Great Britain. GMT was adopted on the Isle of Man in 1883, Jersey in 1898 and Guernsey in 1913. Ireland adopted GMT in 1916, supplanting Dublin Mean Time. Hourly time signals from Greenwich Observatory were first broadcast on 5 February 1924, rendering the time ball at the observatory redundant. The daily rotation of the Earth is irregular (see ΔT) and constantly slows; therefore the atomic clocks constitute a much more stable timebase. On 1 January 1972, GMT was superseded as the international civil time standard by Coordinated Universal"
"Universal Time Universal Time (UT) is a time standard based on Earth's rotation. It is a modern continuation of Greenwich Mean Time (GMT), i.e., the mean solar time on the Prime Meridian at Greenwich, London, UK. In fact, the expression ""Universal Time"" is ambiguous (when accuracy of better than a few seconds is required), as there are several versions of it, the most commonly used being Coordinated Universal Time (UTC) and UT1 (see ). All of these versions of UT, except for UTC, are based on Earth's rotation relative to distant celestial objects (stars and quasars), but with a scaling"
"eventually approved, along with the idea of maintaining the UTC second equal to the TAI second. At the end of 1971, there was a final irregular jump of exactly 0.107758 TAI seconds, so that 1 January 1972 00:00:00 UTC was 1 January 1972 00:00:10 TAI exactly, making the difference between UTC and TAI a whole number of seconds. At the same time, the tick rate of UTC was changed to exactly match TAI. UTC also started to track UT1 rather than UT2. Some time signals started to broadcast the DUT1 correction (UT1 − UTC) for applications requiring a closer approximation"
"historically as an effort which first began as a collaboration between 41 nations, officially agreed to and signed at the International Meridian Conference, in Washington D.C. in 1884. At this conference, the local mean solar time at the Royal Observatory, Greenwich in England was chosen to define the ""universal day"", counted from 0 hours at Greenwich mean midnight. This agreed with the civil Greenwich Mean Time used on the island of Great Britain since 1847. In contrast astronomical GMT began at mean noon, i.e. astronomical day ""X"" began at noon of civil day ""X"". The purpose of this was to"
"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, but the two Nautical Almanac Offices did not accept it until 1952. Civil time In modern usage, civil time refers to statutory time scales designated by civilian authorities,"
"It is also used to refer to Universal Time (UT), which is a standard astronomical concept used in many technical fields and is referred to by the phrase Zulu time. As the United Kingdom grew into an advanced maritime nation, British mariners kept at least one chronometer on GMT in order to calculate their longitude from the Greenwich meridian, which was by convention considered to have longitude zero degrees (this convention was internationally adopted in the International Meridian Conference of 1884). Note that the synchronization of the chronometer on GMT did not affect shipboard time itself, which was still solar"
"Brazil abstained. The French did not adopt the Greenwich meridian as the beginning of the universal day until 1911. Even then it refused to use the name ""Greenwich"", instead using the term ""Paris mean time, retarded by 9 minutes and 21 seconds"". France finally replaced this phrase with ""Coordinated Universal Time"" (UTC) in 1978. Resolution 4 expressly exempts standard time from the universal day. Although two delegates, including Sandford Fleming, proposed the adoption of standard time by all nations, other delegates objected, stating that it was outside the purview of the conference, so neither proposal was subjected to a vote."
"San Marino, Serbia, Slovakia, Slovenia, Spain, Sweden and Switzerland. After World War II Monaco, Andorra and Gibraltar implemented CET. Portugal used CET in the years 1966–1976 and 1992–1996. The time around the world is based on Universal Coordinated Time (UTC) which is roughly synonymous with Greenwich Mean Time (GMT). From late March to late October, clocks in the United Kingdom are put forward by one hour for British Summer Time (BST). Since 1997, most of the European Union aligned with the British standards for BST. In 1968 there was a three-year experiment called ""British Standard Time"", when the UK and"
"a list of the 'incongruencies': Greenwich Mean Time Greenwich Mean Time (GMT) is the mean solar time at the Royal Observatory in Greenwich, London, reckoned from midnight. At different times in the past, it has been calculated in different ways, including being calculated from noon; as a consequence, it cannot be used to specify a precise time unless a context is given. English speakers often use GMT as a synonym for Coordinated Universal Time (UTC). For navigation, it is considered equivalent to UT1 (the modern form of mean solar time at 0° longitude); but this meaning can differ from UTC"
"keep UTC within 0.9 seconds of the UT1 variant of universal time. See the ""Current number of leap seconds"" section for the number of leap seconds inserted to date. The official abbreviation for Coordinated Universal Time is ""UTC"". This abbreviation arose from a desire by the International Telecommunication Union and the International Astronomical Union to use the same abbreviation in all languages. English speakers originally proposed ""CUT"" (for ""coordinated universal time""), while French speakers proposed ""TUC"" (for """"). The compromise that emerged was ""UTC"", which conforms to the pattern for the abbreviations of the variants of Universal Time (UT0, UT1,"
"observations made at the Royal Greenwich Observatory (RGO). The principal meridian of that observatory was chosen in 1884 by the International Meridian Conference to be the Prime Meridian. GMT either by that name or as 'mean time at Greenwich' used to be an international time standard, but is no longer so; it was initially renamed in 1928 as Universal Time (UT) (partly as a result of ambiguities arising from the changed practice of starting the astronomical day at midnight instead of at noon, adopted as from 1 January 1925). The more current refined version of UT, UT1, is still in"
"reality mean time at Greenwich. Greenwich Mean Time is still the legal time in the UK (in winter, and as adjusted by one hour for summer time). But Coordinated Universal Time (UTC) (an atomic-based time scale which is always kept within 0.9 second of UT1) is in common actual use in the UK, and the name GMT is often inaccurately used to refer to it. (See articles Greenwich Mean Time, Universal Time, Coordinated Universal Time and the sources they cite.) Universal Time (UT) is mean solar time at 0° longitude; some implementations are Ephemeris time and its successor time scales"
"local mean solar time at the Royal Observatory, Greenwich in England was chosen to define the Universal day, counted from 0 hours at mean midnight. This agreed with civil Greenwich Mean Time (GMT), used on the island of Great Britain since 1847. In contrast, astronomical GMT began at mean noon, 12 hours ""after"" mean midnight of the same date until 1 January 1925, whereas nautical GMT began at mean noon, 12 hours ""before"" mean midnight of the same date, at least until 1805 in the Royal Navy, but persisted much later elsewhere because it was mentioned at the 1884 conference."
"in the United Kingdom and countries of the Commonwealth, including Australia, New Zealand, South Africa, India, Pakistan, Bangladesh and Malaysia; and in many other countries of the eastern hemisphere. In some countries (the United Kingdom for example) Greenwich Mean Time is the legal time in the winter and the population uses the term. See GMT in legislation, below, for further explanation. As the United Kingdom grew into an advanced maritime nation, British mariners kept at least one chronometer on GMT to calculate their longitude from the Greenwich meridian, which was by convention considered to have longitude zero degrees, internationally adopted"
"noon-based astronomical convention for GMT. The more specific terms UT and UTC do not share this ambiguity, always referring to midnight as zero hours. Legally, the civil time used in the UK is called still ""Greenwich mean time"" (without capitalisation), according to the Interpretation Act 1978, with an exception made for those periods when the Summer Time Act 1972 orders an hour's shift for daylight saving. The Interpretation Act 1978, section 9, provides that whenever an expression of time occurs in an Act, the time referred to shall (unless otherwise specifically stated) be held to be Greenwich mean time. Under"
"in the United Kingdom. Between 18 February 1968 and 31 October 1971, Irish Standard Time was used all year round. In Portugal, CET was used in the mainland from 1966 to 1976 and from 1992 to 1996. The autonomous region of the Azores used WET from 1992 to 1993. These areas are located between 7°30′ W and 22°30′ W (""physical"" UTC) Areas using UTC+1: See Central European Time Western European Time Western European Time (WET, ) is a time zone covering parts of western and northwestern Europe. The following countries and regions use WET in winter months: All the above"
"day and changes of UTC date synchronized with those of UT1 (the solar time standard that superseded GMT). By then, the UTC clock was already 10 seconds behind TAI, which had been synchronized with UT1 in 1958, but had been counting true SI seconds since then. After 1972, both clocks have been ticking in SI seconds, so the difference between their readouts at any time is 10 seconds plus the total number of leap seconds that have been applied to UTC (37 seconds ). The scheduling of leap seconds was initially delegated to the Bureau International de l'Heure (BIH), but"
"hour, and in most cases a multiple of an hour. Universal Time Universal Time (UT) is a time standard based on Earth's rotation. It is a modern continuation of Greenwich Mean Time (GMT), i.e., the mean solar time on the Prime Meridian at Greenwich, London, UK. In fact, the expression ""Universal Time"" is ambiguous (when accuracy of better than a few seconds is required), as there are several versions of it, the most commonly used being Coordinated Universal Time (UTC) and UT1 (see ). All of these versions of UT, except for UTC, are based on Earth's rotation relative to"
"solar time is official. UTC time is based on the SI second, which was first defined in 1967, and is based on the use of atomic clocks. Some other less used but closely related time-standards include International Atomic Time (TAI), Terrestrial Time, and Barycentric Dynamical Time. Between 1967 and 1971, UTC was periodically adjusted by fractional amounts of a second in order to adjust and refine for variations in mean solar time, with which it is aligned. After 1 January 1972, UTC time has been defined as being offset from atomic time by a whole number of seconds, changing only"
"is only uncontroversial when applied to the present form of UTC. The Unix epoch predating the start of this form of UTC does not affect its use in this era: the number of days from 1 January 1970 (the Unix epoch) to 1 January 1972 (the start of UTC) is not in question, and the number of days is all that is significant to Unix time. The meaning of Unix time values below (i.e., prior to 1 January 1972) is not precisely defined. The basis of such Unix times is best understood to be an unspecified approximation of UTC. Computers"
"agreed upon international time. In 1928 Greenwich Mean Time was rebranded for scientific purposes by the International Astronomical Union as Universal Time (UT). This was to avoid confusion with the previous system where the day had begun at noon. As the general public had always begun the day at midnight the timescale continued to be presented to them as Greenwich Mean Time. By 1956, universal time had been split into various versions – UT2, which smoothed for polar motion and seasonal effects, was presented to the public as Greenwich Mean Time. Later, UT1 (which smooths only for polar motion) became"
"the same as in the six EEC countries, except in the summer in Italy, which switched to Central European Summer Time (CEST). One artefact of the 1968 legislation is that ""standard time"" () legally refers to summer time; the 1971 act defined a period of time in the winter as ""winter time"" during which the time observed would be GMT, leaving ""standard time"" unchanged. From the 1980s, the dates of switch between winter and summer time have been synchronised across the European Union. The statutory instruments (SIs) that have been issued under the Standard Time Acts are listed below, in"
"Ireland experimentally employed British Summer Time (GMT+1) all year round; clocks were put forward in March 1968 and not put back until October 1971. Central European Time is sometimes referred to as continental time in the UK. Several African countries use all year long, where it called West Africa Time (WAT), although Algeria, Morocco and Tunisia also use the term ""Central European Time"", despite being located in North Africa. Between 2005 and 2008, Tunisia observed daylight saving time. Libya also used CET during the years 1951–1959, 1982–1989, 1996–1997 and 2012–2013. For other countries see and West Africa Time. Legal, political"
"onwards. Prior to that, since 1 January 1961 there was an older form of UTC in which not only were there occasional time steps, which were by non-integer numbers of seconds, but also the UTC second was slightly longer than the SI second, and periodically changed to continuously approximate the Earth's rotation. Prior to 1961 there was no UTC, and prior to 1958 there was no widespread atomic timekeeping; in these eras, some approximation of GMT (based directly on the Earth's rotation) was used instead of an atomic timescale. The precise definition of Unix time as an encoding of UTC"