Greenwich Time Signal
Encyclopedia
The Greenwich Time Signal (GTS), popularly known as the pips, is a series of six short tones broadcast at one-second intervals by many BBC Radio
BBC Radio
BBC Radio is a service of the British Broadcasting Corporation which has operated in the United Kingdom under the terms of a Royal Charter since 1927. For a history of BBC radio prior to 1927 see British Broadcasting Company...

 stations to mark the precise start of each hour. First introduced in 1924, the viability of continued use of the time signal on radio is under discussion, as the unavoidable time lags associated with digital broadcasting systems make its use less feasible as an aid to calibration
Calibration
Calibration is a comparison between measurements – one of known magnitude or correctness made or set with one device and another measurement made in as similar a way as possible with a second device....

.

Structure

There are six pips (short beeps) in total, which occur on the 5 seconds leading up to the hour and on the hour itself. Each pip is a 1 k
SI prefix
The International System of Units specifies a set of unit prefixes known as SI prefixes or metric prefixes. An SI prefix is a name that precedes a basic unit of measure to indicate a decadic multiple or fraction of the unit. Each prefix has a unique symbol that is prepended to the unit symbol...

Hz
Hertz
The hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications....

 tone (about half way between musical B5 and C6), which, for the first five, last a tenth of a second, while the final pip lasts half a second. The actual moment when the hour changes – the "on-time marker" – is at the very beginning of the last pip.

When a leap second
Leap second
A leap second is a positive or negative one-second adjustment to the Coordinated Universal Time time scale that keeps it close to mean solar time. UTC, which is used as the basis for official time-of-day radio broadcasts for civil time, is maintained using extremely precise atomic clocks...

 occurs (exactly one second before midnight), it is indicated by a seventh pip. In this case the first pip occurs at 23:59:55 (as usual) and there is a sixth short pip at 23:59:60 (the leap second) followed by the long pip at 00:00:00. The leap second is also the explanation for the final pip being longer than the others. This is so that it is always clear which pip is on the hour, especially where there is an extra pip that some people might not be expecting. Before leap seconds were conceived the final pip was the same length as the others. Leap seconds can also be used to make the year shorter, but in practice this has never happened.

Although normally broadcast only on the hour by BBC domestic radio, BBC World Service use the signal at other times as well. The signal is generated at each quarter hour and have on occasion been broadcast in error.

Usage

The pips are used by several stations, but not always at every hour. On Radio 4
BBC Radio 4
BBC Radio 4 is a British domestic radio station, operated and owned by the BBC, that broadcasts a wide variety of spoken-word programmes, including news, drama, comedy, science and history. It replaced the BBC Home Service in 1967. The station controller is currently Gwyneth Williams, and the...

, the pips broadcast every hour, except when they are replaced at the start of the 6pm and midnight news bulletins (and the start of the Westminster Hour on Sundays at 10pm) by the Westminster chimes from the Clock Tower at the Palace of Westminster
Palace of Westminster
The Palace of Westminster, also known as the Houses of Parliament or Westminster Palace, is the meeting place of the two houses of the Parliament of the United Kingdom—the House of Lords and the House of Commons...

, with the hour chimes of Big Ben, sometimes called the "bongs" (though these are more associated in the popular mind with ITV
ITV
ITV is the major commercial public service TV network in the United Kingdom. Launched in 1955 under the auspices of the Independent Television Authority to provide competition to the BBC, it is also the oldest commercial network in the UK...

's News at Ten
News at Ten
The ITV News at Ten is the flagship news programme on British television network ITV, produced by ITN and founded by news editor Geoffrey Cox in 1967. It was originally planned as a thirteen week project in July 1967 because senior figures at ITV refused to believe that a permanent 30-minute late...

).

In 1999, pip-like sounds were incorporated into the themes written by composer David Lowe to introduce BBC Television News
BBC News
BBC News is the department of the British Broadcasting Corporation responsible for the gathering and broadcasting of news and current affairs. The department is the world's largest broadcast news organisation and generates about 120 hours of radio and television output each day, as well as online...

 programmes. They are still used today on BBC One
BBC One
BBC One is the flagship television channel of the British Broadcasting Corporation in the United Kingdom. It was launched on 2 November 1936 as the BBC Television Service, and was the world's first regular television service with a high level of image resolution...

, BBC World News and BBC News. The pips can also be heard every hour on the BBC's worldwide radio station BBC World Service
BBC World Service
The BBC World Service is the world's largest international broadcaster, broadcasting in 27 languages to many parts of the world via analogue and digital shortwave, internet streaming and podcasting, satellite, FM and MW relays...

.

The pips are used on Radio 1
BBC Radio 1
BBC Radio 1 is a British national radio station operated by the British Broadcasting Corporation which also broadcasts internationally, specialising in current popular music and chart hits throughout the day. Radio 1 provides alternative genres after 7:00pm including electronic dance, hip hop, rock...

 during The Chris Moyles Show
The Chris Moyles Show
The Chris Moyles Show is the current BBC Radio 1 breakfast show in the UK, and has been since Chris Moyles became the station's breakfast show presenter on 5 January 2004. From 2004 to 2007, the show was broadcast 6:55–10:00 am each weekday, but since 15 October 2007 it has started from...

at 6.30am just after the news, 9am as part of the Tedious Link feature, 10am (at the end of the show) and often before Newsbeat
Newsbeat
Newsbeat is the flagship news programme on BBC Radio 1 and BBC Radio 1Xtra. Newsbeat is produced by BBC News but differs from the BBC's other news programmes in its remit to provide news tailored for a specifically younger audience....

. As most stations only air the pips on the hour, the Chris Moyles show is the only show where the pips are broadcast on the half hour. Masterpieces, the playing of an album in its entirety, is begun with pips, and they also feature at 7pm on Fridays to signify the start of the weekend and at 4pm on Sundays to mark the start of The Official Chart Show, and at 4pm on Wednesday to mark the end of The Official Chart Update. The pips are also used at 7pm on Saturday evenings at the start of Radio 1's 12-hour simulcast with digital station BBC 1Xtra.

The pips are used on Radio 2
BBC Radio 2
BBC Radio 2 is one of the BBC's national radio stations and the most popular station in the United Kingdom. Much of its daytime playlist-based programming is best described as Adult Contemporary or AOR, although the station is also noted for its specialist broadcasting of other musical genres...

 at 7am and 8am during The Chris Evans Breakfast Show and at 5pm between Steve Wright's and Simon Mayo
Simon Mayo
Simon Mayo is an English radio presenter who has worked for BBC Radio since 1981. As of January 2010, Mayo is presenter of Simon Mayo Drivetime on BBC Radio 2 and, with Mark Kermode, presenter of Kermode and Mayo's Film Reviews on BBC Radio 5 Live.In 2008, Mayo was recognised as the "radio...

's show. They are also broadcast during Zoe Ball
Zoë Ball
Zoë Louise Ball is an English television and radio personality, most famous for becoming the first female host of the BBC Radio 1 breakfast show and for her earlier work presenting the 1990s children's show, Live & Kicking.-TV career:The daughter of the children's TV presenter Johnny Ball and his...

's show at 7am and 8am on a Saturday and at 8am and 9am on a Sunday during Aled Jones
Aled Jones
Aled Jones is a Welsh singer and television/radio personality, broadcaster and television presenter who first came to fame as a treble...

' show. Radio 2's coverage of the Eurovision Song Contest
Eurovision Song Contest
The Eurovision Song Contest is an annual competition held among active member countries of the European Broadcasting Union .Each member country submits a song to be performed on live television and then casts votes for the other countries' songs to determine the most popular song in the competition...

 is preceded by the pips.

The pips were used on 5 Live
BBC Radio 5 Live
BBC Radio 5 Live is the BBC's national radio service that specialises in live BBC News, phone-ins, and sports commentaries...

 at 12:30am in the early hours of Tuesday to Friday to signify the start of the Special Half Hour segment on Richard Bacon's late evening show.

The BBC does not allow the pips to be broadcast except as a time signal. Plays and comedies which have fictional news programmes use various methods to avoid playing the full six pips, ranging from simply fading in the pips to a version played on On the Hour
On the Hour
On the Hour was a British radio programme that parodied current affairs broadcasting, broadcast on BBC Radio 4 between 1991 and 1992.Written by Chris Morris, Armando Iannucci, Steven Wells, Andrew Glover, Stewart Lee, Richard Herring and David Quantick, it starred Morris as the overzealous and...

in which the sound was made into a small tune between the pips.

Accuracy

The pips for national radio stations and some local radio stations are timed relative to UTC, from an atomic clock
Atomic clock
An atomic clock is a clock that uses an electronic transition frequency in the microwave, optical, or ultraviolet region of the electromagnetic spectrum of atoms as a frequency standard for its timekeeping element...

 in the basement of Broadcasting House
Broadcasting House
Broadcasting House is the headquarters and registered office of the BBC in Portland Place and Langham Place, London.The building includes the BBC Radio Theatre from where music and speech programmes are recorded in front of a studio audience...

 synchronised with the National Physical Laboratory
National Physical Laboratory, UK
The National Physical Laboratory is the national measurement standards laboratory for the United Kingdom, based at Bushy Park in Teddington, London, England. It is the largest applied physics organisation in the UK.-Description:...

's Time from NPL and GPS. On other stations, the pips are generated locally from a GPS-synchronised clock.

The BBC compensates for the time delay in both broadcasting and receiving equipment, as well as the time for the actual transmission. The pips are timed so that they are accurately received on long wave as far as 160 kilometre from the Droitwich AM transmitter
Droitwich AM transmitter
The Droitwich transmitting station is a large broadcasting facility for longwave and mediumwave transmissions, established in 1934 in the civil parish of Dodderhill, just outside the village of Wychbold, which is near Droitwich, Worcestershire, England...

, which is the distance to Central London
Central London
Central London is the innermost part of London, England. There is no official or commonly accepted definition of its area, but its characteristics are understood to include a high density built environment, high land values, an elevated daytime population and a concentration of regionally,...

.

As a pre-IRIG
IRIG
The Inter Range Instrumentation Group is the standards body of the Range Commanders Council . They publish a number of standards through the RCC Secretariat at White Sands Missile Range ....

 and pre-NTP time transfer and transmission system, the pips have been a great technological success. In modern times, however, time can be transferred to systems with CPUs and operating systems by using BCD or some Unix Time variant.

Newer digital broadcasting methods have introduced even greater problems for the accuracy of use of the pips. On digital platforms such as DVB, DAB
Digital audio broadcasting
Digital Audio Broadcasting is a digital radio technology for broadcasting radio stations, used in several countries, particularly in Europe. As of 2006, approximately 1,000 stations worldwide broadcast in the DAB format....

, satellite and the Internet, the pips—although generated accurately—are not heard by the listener exactly on the hour. The encoding and decoding
Codec
A codec is a device or computer program capable of encoding or decoding a digital data stream or signal. The word codec is a portmanteau of "compressor-decompressor" or, more commonly, "coder-decoder"...

 of the digital signal causes a delay, of usually between 2 and 8 seconds. In the case of satellite broadcasting, the travel time
Travel time
Travel time may refer to* Travel, movement of people between locations* Travel journal, record made by a voyager* Propagation speed, term in physics to measure things such as the speed of light or radio waves...

 of the signal to and from the satellite adds about another 0.25 seconds.

DVB, DAB (Eureka 147 and Digital Radio Mondiale
Digital Radio Mondiale
Digital Radio Mondiale is a set of digital audio broadcasting technologies designed to work over the bands currently used for AM broadcasting, particularly shortwave...

) and FM Radio Data System
Radio Data System
Radio Data System, or RDS, is a communications protocol standard for embedding small amounts of digital information in conventional FM radio broadcasts. RDS standardises several types of information transmitted, including time, station identification and programme information.Radio Broadcast Data...

 all support separate time signal transmission subsystems with accuracy equal to or several orders of magnitude better than the pips, so the listener need not worry about decoding the pips to synchronize the clocks on these systems.

History

The pips have been broadcast daily since 5 February 1924,
and were the idea of the Astronomer Royal
Astronomer Royal
Astronomer Royal is a senior post in the Royal Household of the Sovereign of the United Kingdom. There are two officers, the senior being the Astronomer Royal dating from 22 June 1675; the second is the Astronomer Royal for Scotland dating from 1834....

, Sir Frank Watson Dyson
Frank Watson Dyson
Sir Frank Watson Dyson, KBE, FRS was an English astronomer and Astronomer Royal who is remembered today largely for introducing time signals from Greenwich, England, and for the role he played in testing Einstein's theory of general relativity.- Biography :Dyson was born in Measham, near...

, and the head of the BBC, John Reith
John Reith
John Reith may refer to:*John Reith, 1st Baron Reith , Scottish broadcasting executive*John Reith...

. The pips were originally controlled by two mechanical clocks located in the Royal Greenwich Observatory that had electrical contacts attached to their pendula
Pendulum
A pendulum is a weight suspended from a pivot so that it can swing freely. When a pendulum is displaced from its resting equilibrium position, it is subject to a restoring force due to gravity that will accelerate it back toward the equilibrium position...

. Two clocks were used in case of a breakdown of one. These sent a signal each second to the BBC, which converted them to the audible oscillatory tone broadcast.

The Royal Greenwich Observatory moved to Herstmonceux Castle
Herstmonceux Castle
Herstmonceux Castle is a brick-built Tudor castle near Herstmonceux, East Sussex, United Kingdom. From 1957 to 1988 its grounds were the home of the Royal Greenwich Observatory...

 in 1957 and the GTS equipment followed a few years later in the form of an electronic clock. Reliability was improved by renting two lines for the service between Herstmonceux and the BBC, with a changeover between the two at Broadcasting House
Broadcasting House
Broadcasting House is the headquarters and registered office of the BBC in Portland Place and Langham Place, London.The building includes the BBC Radio Theatre from where music and speech programmes are recorded in front of a studio audience...

 if the main line become disconnected.

The tone sent on the lines was inverted: the signal sent to the BBC was a steady 1 kHz tone when no pip was required, and no tone when a pip should be sounded. This let faults on the line be detected immediately by automated monitoring for loss of audio.

The Greenwich Time Signal was the first sound heard in the handover to the London 2012 Olympics during the Beijing 2008 Olympics Closing Ceremony.

The pips were also broadcast by the BBC Television Service, but this practice was discontinued by the 1960s.

Crashing the pips

The BBC
BBC
The British Broadcasting Corporation is a British public service broadcaster. Its headquarters is at Broadcasting House in the City of Westminster, London. It is the largest broadcaster in the world, with about 23,000 staff...

 discourages any other sound being broadcast at the same time as the pips; doing so is commonly known as 'crashing the pips'. This was most often referred to on Terry Wogan's show, Wake Up to Wogan
Wake Up to Wogan
Wake Up to Wogan was the most listened to radio show in the United Kingdom and the flagship breakfast programme broadcast on BBC Radio 2. The show was presented by Sir Terry Wogan who fronted WUTW from 4 January 1993; he had previously presented the breakfast show between 1972 and 1984, but the...

, although usually only in jest since the actual event happens rarely. Different BBC Radio stations approach this issue differently. BBC Radio 1 has a more laid-back approach with the pips, the most notable example being The Chris Moyles Show
The Chris Moyles Show
The Chris Moyles Show is the current BBC Radio 1 breakfast show in the UK, and has been since Chris Moyles became the station's breakfast show presenter on 5 January 2004. From 2004 to 2007, the show was broadcast 6:55–10:00 am each weekday, but since 15 October 2007 it has started from...

which usually plays the pips over a currently playing song or a jingle 'bed' (background music from a jingle) which climaxes into the jingle after the pips end. Many BBC local radio stations also play the pips over the station's jingle. BBC Radio 4 is stricter. It is an almost entirely speech-based network; incidents at the end of the Today programme regularly cause listeners' complaints.

As a contribution to the 2005 Red Nose Day, the BBC
BBC
The British Broadcasting Corporation is a British public service broadcaster. Its headquarters is at Broadcasting House in the City of Westminster, London. It is the largest broadcaster in the world, with about 23,000 staff...

 developed a "pips" ring-tone.
On the 2009 Red Nose Day, well-known comedians replaced the continuity announcers for most of the daytime output of Radio 4 and, it seems, deliberately crashed the pips—the first crash by Jo Brand
Jo Brand
Josephine Grace "Jo" Brand is a BAFTA winning British comedian, writer, and actor.- Early life :Jo Brand was born 23 July 1957 in Wandsworth, London. Her mother was a social worker. Brand is the middle of three children, with two brothers...

 was perhaps a genuine mistake, but as the day progressed every other announcer did the same.

Bill Bailey
Bill Bailey
Bill Bailey is an English comedian, musician and actor. As well as his extensive stand-up work, Bailey is well known for his appearances on Black Books, Never Mind the Buzzcocks, Have I Got News for You, and QI.Bailey was listed by The Observer as one of the 50 funniest acts in British comedy in...

's BBC Rave includes the BBC News theme, which incorporates a variant of the pips (though not actually broadcast exactly on the hour). The footage can be seen on his DVD Part Troll.

In the late 1980s Radio 1 featured the pips played over a station jingle
Jingle
A jingle is a short tune used in advertising and for other commercial uses. The jingle contains one or more hooks and lyrics that explicitly promote the product being advertised, usually through the use of one or more advertising slogans. Ad buyers use jingles in radio and television...

 during Jakki Brambles
Jakki Brambles
Jackie Brambles , formerly known as Jakki Brambles, is an English journalist, radio DJ and television presenter.-Early life and early career:...

' early show and Simon Mayo
Simon Mayo
Simon Mayo is an English radio presenter who has worked for BBC Radio since 1981. As of January 2010, Mayo is presenter of Simon Mayo Drivetime on BBC Radio 2 and, with Mark Kermode, presenter of Kermode and Mayo's Film Reviews on BBC Radio 5 Live.In 2008, Mayo was recognised as the "radio...

's breakfast show. This was not strictly crashing the pips as they were not intended to be, or mistaken for, an accurate time signal.

Technical problems

At 8am on 17 September 2008, to the surprise of John Humphrys
John Humphrys
Desmond John Humphrys , is a Welsh-born British author, journalist and presenter of radio and television, who has won many national broadcasting awards...

, the day's main presenter on the Today programme, and Johnnie Walker
Johnnie Walker (DJ)
Johnnie Walker MBE is a popular British veteran radio disc jockey and broadcaster....

, who was standing in for Terry Wogan on Radio 2, the pips went adrift by 6 seconds, and broadcast seven pips rather than six. This was traced to a problem with the pip generator, which was 'repaired' by switching it off and on again. Part of Humphrys' surprise was probably because of his deliberate avoidance of crashing the pips with the help of an accurate clock in the studio.

A sudden total failure in the generation of the audio pulses that constitute the pips was experienced on 31 May 2011 and silence was unexpectedly broadcast in place of the 17:00 signal. The problem was traced to the power supply of the equipment which converts the signal from the atomic clocks into an audible signal. Whilst repairs were underway the BBC elected to broadcast a "dignified silence" in place of the pips at 19:00. By 19:45 the same day the power supply was repaired and the 20:00 pips were broadcast as normal.

Similar time signals elsewhere

Many radio broadcasters around the world use the Greenwich Time Signal as a means to mark the start of the hour. The pips are both used in domestic and international commercial and public broadcasting. Many radio stations use six tones similar to those used by the BBC World Service; some shorten it to five, four, or three tones.

In Hong Kong
Hong Kong
Hong Kong is one of two Special Administrative Regions of the People's Republic of China , the other being Macau. A city-state situated on China's south coast and enclosed by the Pearl River Delta and South China Sea, it is renowned for its expansive skyline and deep natural harbour...

 pips are used on RTHK's radio channels for the same purpose and in the same way. The signals, which are provided by the Hong Kong Observatory
Hong Kong Observatory
Hong Kong Observatory is a department of the Hong Kong government. The Observatory forecasts weather and issues warnings on weather-related hazards...

, are broadcast every half hour during the day and on the hour at night, immediately before the news headline reports.

In Finland
Finland
Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...

 on YLE's radio services the pips are broadcast on the hour.

In The Netherlands
Netherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...

 only three pips are used. There used to be six, however it was felt that people would lose count, so now only three are used.

In Catalonia
Catalonia
Catalonia is an autonomous community in northeastern Spain, with the official status of a "nationality" of Spain. Catalonia comprises four provinces: Barcelona, Girona, Lleida, and Tarragona. Its capital and largest city is Barcelona. Catalonia covers an area of 32,114 km² and has an...

, Spain the pips are broadcast every half hour, even by music stations, regardless of the material being transmitted. Dance music station Flaix FM and Hot AC station Ràdio Flaixbac, both owned by the same media group, every half hour broadcast a very short sequence of two very short tones followed by a longer one, the whole lasting not more than one and a half seconds.

In Malaysia, RTM
Radio Televisyen Malaysia
The Department of Broadcasting, Malaysia, DBA Radio Televisyen Malaysia , is a Malaysian state-owned public broadcaster. It owns and operates a number of radio and television stations in Malaysia, based in Kuala Lumpur...

 radio stations use the pips hourly before the news broadcast but only two pips are sounded, which is a short pip on the 59th second before the hour and a longer pip on the top of the hour. In the past, the pips were used to sound similar to the BBC's.

In Ireland
Ireland
Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

, six pips are broadcast before news bulletins at 07:00, 13:00 and 24:00 on RTÉ Radio 1
RTÉ Radio 1
RTÉ Radio 1 is the principal radio channel of Irish public-service broadcaster Raidió Teilifís Éireann and is the direct descendant of Dublin radio station 2RN, which began broadcasting on a regular basis on 1 January 1926...

.

In the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, the pips can be heard on the Middlebury College
Middlebury College
Middlebury College is a private liberal arts college located in Middlebury, Vermont, USA. Founded in 1800, it is one of the oldest liberal arts colleges in the United States. Drawing 2,400 undergraduates from all 50 United States and over 70 countries, Middlebury offers 44 majors in the arts,...

 radio station WRMC
WRMC
WRMC-FM is the full power, student-volunteer-run radio station of Middlebury College. WRMC broadcasts a variety of content types, including talk, news, and radio drama, although the vast majority of the schedule is music of all genres...

.

Radio New Zealand National, the New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

 equivalent of BBC Radio 4, plays the same BBC pips at the top of every hour.

See also

  • MSF time signal
  • National Research Council Time Signal
    National Research Council Time Signal
    The National Research Council Time Signal is Canada's longest running but shortest radio programme. Heard every day since November 5, 1939 , shortly before 13:00 Eastern Time across the CBC Radio One network, it lasts between 15 and 45 seconds, ending exactly at 13:00...

     - A CBC Radio One
    CBC Radio One
    CBC Radio One is the English language news and information radio network of the publicly-owned Canadian Broadcasting Corporation. It is commercial free and offers both local and national programming...

    indicator for 1300 ET

External links

  • http://www.miketodd.net/other/gts.htm
  • http://www.radionetherlands.nl/features/media/practical/time.html
  • http://www.clockco.co.uk/article_info.php?articles_id=15
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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