A speaking clock or talking clock is a live or recorded human voice service, usually accessed by telephone, that gives the correct time. The first telephone speaking clock service was introduced in France, in association with the Paris Observatory, on 14 February 1933.
The format of the service is similar to that of radio time signal services. At set intervals (e.g. ten seconds) a voice announces (for example) "At the third stroke, the time will be twelve forty-six and ten seconds...", with three beeps following. Some countries have sponsored time announcements and include the sponsor's name in the message.
List by countryEdit
In Australia, the number 1194 was the speaking clock in all areas. The service started in 1953 by the Post Master General's Department, originally to access the talking clock on a rotary dial phone, callers would dial "B074", during the transition from a rotary dial to a DTMF based phone system, the talking clock number changed from "B074" to 1194. It was always the current time from where the call originated, in part due to Telstra's special call routing systems. Landline, Payphone and Mobile customers who called the 1194 time service would receive the time. A male voice, often known by Australians as "George", would say "At the third stroke, it will be (hours) (minutes) and (seconds) seconds/precisely. (three beeps)" e.g. "At the third stroke, it will be three thirty three and forty seconds". The time announcement was announced in 10 second increments and the beep was 1 kHz. Originally there was only one stroke eg:”At the stroke, it will be...” etc.
Prior to automatic systems, the subscriber rang an operator who would quote the time from a central clock in the exchange with a phrase such as "The time by the exchange clock is ...". This was not precise and the operator could not always answer when the subscriber wanted. In 1954, British-made systems were installed in Melbourne (1st floor, City West Exchange) and Sydney. The mechanical speaking clock used rotating glass discs where different parts of the time were recorded on the disc. A synchronous motor drove the disc with the driving source derived from a 5 MHz quartz oscillator via a multi stage valve divider. This was amplified to give sufficient impetus to drive the motor. Because of the low torque available, a hand wheel was used to spin the motor on start up. The voice was provided by Gordon Gow. The units were designed for continuous operation. Both units in Melbourne and Sydney were run in tandem (primary and backup). For daylight saving time changes, one would be on line while the second was advanced or delayed by one hour and at the 02:00:00 Australian Eastern Standard time, would be switched over to the standby unit.
In addition to the speaking clocks, there was ancillary equipment to provide timing signals, 1 pulse per second, 8 pulses per minute and 8 pulses per hour. The Time and Frequency Standards Section in the PMG Research Laboratories at 59 Little Collins Street, Melbourne maintained the frequency checks to ensure that the system was "on time". From a maintenance point of view, the most important part of the mechanical clocks was to ensure that they were well oiled to minimise wear on the cams and to replace blown bulbs in the optical pickups from the glass disk recordings. When Time & Frequency Standards moved from 59 Collins Street to Clayton Research Labs (3rd Flr. Building M5) , the control signals were duplicated and a second bank of Caesium Beam Primary standards installed so the cutover was transparent with no loss of service.
This mechanical system was replaced with a digital system in 1990. Each speaking clock ensemble consisted of two announcing units (Zag 500), a supervisory unit (CCU 500), two phase-locked oscillators, two pulse distribution units, a Civil Time Receiver (plus a spare), and two or four Computime 1200 baud modems. The voice was provided by Richard Peach, a former ABC broadcaster. The various components were sent for commercial production after a working prototype was built in the Telstra Research Laboratory (TRL). Assmann Australia used a German announcing unit and built a supervisory unit to TRL specifications. Design 2000 incorporated TRL oscillators in the phase locked oscillator units designed at TRL and controlled by two tone from the Telstra Caesium beam frequency standards. Ged Company built civil time receivers. The civil time code generators and two tone generators were designed and built within TRL. The changeover occurred at 12 noon, September 12, 1990.
Each state capital had a digital speaking clock for the local time of day with one access number for all Australia, 1194. In 2002 the Telstra 1194 service was migrated to Informatel (which uses its own digital technology, in conjunction with the National Measurement Institute — but kept the original voice of Richard Peach), whilst the other time services (e.g. hourly pips to radio stations) were retained as a service by Telstra. In May 2006 the remaining Telstra services were withdrawn and the digital hardware was decommissioned. Telstra ended the 1194 service on the midnight of October 1, 2019 and Australians no longer have access to this service. A web-based simulation of the 1194 service was created by musician Ryan Monro on the day of the original service's shutdown.
In Belgium, the speaking clock used to be reachable on the numbers 1200 (Dutch language), 1300 (French language), and 1400 (German language). Starting September 2012, the service is only reachable on the numbers +32 78 05 12 00 (Dutch Language), +32 78 05 13 00 (French language) and +32 78 05 14 00 (German language). At the time of the number change, the service received 5,000 calls per day.
The NRC provides a Telephone Talking Clock service; voice announcements of Eastern Time are made every 10 seconds, followed by a tone indicating the exact time. This service is available to the general public by dialing +1 613 745-1576 for English service and +1 613 745-9426 for French service. Long-distance charges apply for those calling from outside the Ottawa/Gatineau area. The voices of the time announcements are Harry Mannis in English and Simon Durivage in French.
Dialling 117 in any city connects to a speaking clock that tells the current time in China. Despite China spanning five time zones, only one time is kept over the country, therefore only one zone related service is required and the same time would be announced regardless of where the call was made. Rates are charged according to the ordinary local number, generally around 0.25 RMB/minute.
In Finland the speaking clock service is known as Neiti Aika in Finnish or Fröken Tid in Swedish, both of which mean "Miss Time". The first Neiti Aika service was started in 1936 and was the first automated phone service in Finland. The service is provided by regional phone companies and can be reached by dialling 10061 from any part of the country. The voice of the speaking clock is male or female depending on the phone company service. Nowadays[when?] the use of the Neiti Aika service has decreased significantly, and the press officer of Auria, the regional phone company of Turku, stated in an article of the Turun Sanomat newspaper that when the company started the service in 1938 it was used 352,310 times in its starting year, compared to 1,300 times in September 2006.
In France, the speaking clock (horloge parlante) has been in service since 14 February 1933. It is available on 36.99 from within France, and was formerly available from overseas by dialing +33 8.36.99. - - . - - (where the - - could be any number). However, since September 2011 calls placed from outside France only work from some countries and networks.
In Ireland, the speaking clock (Irish: clog labhartha) was first offered by P&T in 1970, and was reached by dialling 1191. It announced the time in 24-hour format, in English only, at ten second intervals punctuated by a high pitched signal, as follows: “At the signal it will be HH:MM and .. seconds (signal). P&T operator Frances Donegan was the original voice. Antoinette Rocks, also a P&T/Telecom Éireann operator, provided the voice of the speaking clock when it was updated to digital technology in 1980. Her voice was selected as part of a competition on a radio phone-in show, RTÉ Radio 1’s Morning Call with Mike Murphy. Listeners voted for one of 8 voices. At its peak, it received almost three million calls a year (about 8,000 a day). The Irish speaking clock service was permanently shut down by eir (P&T’s successor) on 27 August 2018 due to lack of use and reliance on ageing equipment.
In Italy, the number of the speaking clock ("il numero dell'ora esatta", "the exact time number") was originally 16, the time was given by a recorded female voice. In the mid-seventies, 16 was replaced by 161. Presently, the number to be dialled is 4261.
In 1934, electronic engineer and inventor F.H. Leeuwrik built a speaking clock for the municipal telephone service of The Hague using optically recorded speech, looping on a large drum. The female voice was provided by the then 24-year-old school teacher Cor Hoogendam, hence the machine was nicknamed Tante Cor (Aunt Cor).
In 1969, this system was replaced by a magnetic disk machine resembling a record player with three pick-up arms, telling the time at 10 second intervals followed by a beep. The text was spoken by actress Willie Brill. The service was now called over 130 million times a year.
In April 1992, the machinery was replaced by a digital device with no moving parts. The voice was provided by actress Joke Driessen and the clock's accuracy is maintained by linking it to the German longwave radio transmitter DCF77. To comply with international guidelines limiting double-zero to use as an international prefix, the 002 number was changed on 3 December 1990 to 06-8002, and later to 0900-8002. The service still receives approximately four million calls a year.
The speaking clock in New Zealand is run by the Measurement Standards Laboratory of New Zealand. The service is reached by dialling 0900 45 678 (calls are 99c per minute). MSL has been running the service since 1989.
The speaking clock in Poland is known as Zegarynka which means the clock girl. The service became first available in 1936, using a device invented and patented in Poland. It was speaking with the recorded voice of actress Lidia Wysocka. The first cities to be equipped with this device were Katowice, Warszawa (dialing number 05), Gdynia, Toruń and Kraków (July 1936).
In 1935, Soviet Central Scientific Research Institute of Communications received a government order to design the "Speaking Clock" for Moscow City Telephone Network. "Speaking Clock" was constructed based on cinematic techniques and consists of discs with pulse-density modulation optical marks on photographic tapes, photocell with actuator, and audio tube amplifier. On May 14, 1937 "speaking clock" connected to Moscow City Telephone Network for test operation and it was reachable on the numbers Russian: "Г 1-98-48" and Russian: "Г 1-98-49". It was speaking with the recorded voice of Soviet actor and broadcaster Emmanuil Tobiash. In 1937, the first cities to be equipped with this devices were Moscow and Leningrad.
To hear the current time in Russia, either 100 or 060 can be dialed, depending on the city where this service is available. These calls are free if made from non-mobile phones. In Moscow, the Speaking Clock number is 100 if dialed from within the city, or +7-495-100-. . . . from other countries (where . . . . can be any number). At one time in Moscow, there were advertisements before and after the announcement of the current time; this practice has since ceased.
The speaking clock in Sweden is run by Telia and can be reached by calling 90 510 from landline phones or 08-90 510 from mobile phones. The service is called Fröken Ur which means Miss Clock. It has been in use since 1934. Various voices have stated the time. Since 2000 the voice which states the time belongs to Johanna Hermann Lundberg. In 1977 the speaking clock in Sweden received 64 000 000 calls - which is the record for a year. In 2020 the number of calls was about 2 000 per day, meaning a total of a bit less than 1 000 000 calls annually.
The speaking clock in South Africa is run by Telkom, the country's national telecommunications provider, and can be reached by dialling 1026 either from a fixed line or a cellular phone. The time is announced every 10 seconds and alternates between English and Afrikaans languages. An example of an English announcement of the time would be: "When you hear the signal, it will be four hours, fifteen minutes and ten seconds", followed by a short audible tone to signal the exact time previously announced. The voice of the announcements is that of broadcaster and voiceover artist Helen Naudé. Recorded in 1989, the same speaking clock announcements with Naudé's voice are still in use to the present day. Naudé also provided her voice talent to other Telkom services, such as 1023 directory enquiries, as well as the pre-recorded message "The subscriber you have dialled does not exist", which can be heard when dialling an invalid phone number.
At the third stroke, the time from BT will be (hour) (minute) and (second) seconds.
The service was started in 1936 by the General Post Office (which handled telephones at that time) and was continued by BT after its formation in 1980 and privatisation in 1984. Between 1986 and 2008, the message included the phrase "sponsored by Accurist"; Accurist withdrew their sponsorship in 2008. The "from BT" part was added, then removed at some point, then reinstated.
For times that are an exact minute, "precisely" is substituted for the seconds portion of the announcement. Similarly, announcements for times between the hour and one minute past the hour substitute "o'clock" for the (zero) minutes. Other operators run their own speaking clocks, with broadly similar formats, or redirect to BT's service. Virgin Media have their own service available by dialling 123 from a Virgin Media line. Sky also have their own service accessible by dialling 123 from a Sky telephone line. Dialling 123 from a few mobile services, such as O2, also obtains a speaking clock service. The Giffgaff network uses the same service as O2. The service is not available on the 3 mobile telephone network, as they use 123 as the number for their voicemail services. It was also unavailable on the Orange network for the same reason.
On the occasion of a leap second, such as at 23:59:60 on December 31, 2005, there is an extra second pause between the second and third beeps, to keep the speaking clock synchronised with Coordinated Universal Time: "At the third stroke, the time from BT will be, twelve o'clock precisely. Beep, Beep, <pause> Beep." The current UK time source is the National Physical Laboratory, UK.
In 2011, the BBC reported: "The service still receives 30 million calls each year."
A speaking clock service was first introduced in the United Kingdom on July 24, 1936. The mechanism used was an array of motors, glass discs, photocells and valves which took up the floorspace of a small room. The voice was that of London telephonist Ethel Jane Cain, who had won a prize of 10 guineas (equivalent to £730 in 2020) in a competition to find the "Golden Voice". Cain's voice was recorded optically onto the glass disks in a similar way to a film soundtrack. The service was obtained by dialling the letters TIM (846) on a dial telephone, and hence the service was often colloquially referred to as "Tim". However this code was only used in the telephone systems of the cities of London, Birmingham, Edinburgh, Glasgow, Liverpool and Manchester. Other areas initially dialled 952, but with the introduction of subscriber trunk dialling it was changed to 808 and later 8081 as more 'recorded services' were introduced. It was standardised to 123 by the early 1990s.
The time announcements were made by playing short, recorded phrases or words in the correct sequence. In an interview with Manchester Radio in 1957 Miss Cain said:
The way I recorded it was in jerks as it were. I said: "At the Third Stroke" (that does for all the times), and then I counted from One, Two, Three, Four, for the hours, we even went as far as twenty-four, in case the twenty-four-hour clock should need to be used, and then I said "...and ten seconds, and twenty seconds, and thirty, forty, fifty seconds", and "o'clock" and "precisely". The famous "precisely". So what you hear is "At the Third Stroke it will be one, twenty-one and forty seconds".
In 1963, the original device was replaced by more modern recording technology using a magnetic drum, similar to the Audichron technology used in the United States. The company that manufactured the rotating magnetic drum part of the Speaking Clock was Roberts & Armstrong (Engineers) Ltd of North Wembley. They took on the licence from the British Post Office to manufacture complete clocks for the telecommunications authorities of Denmark, Sweden and the Republic of Ireland, and a third (spare) clock for the British Post Office. The latter was installed in Bow Street, London. The European clocks were modified for the 24-hour system by lengthening the drum and adding extra heads. Roberts & Armstrong subcontracted the electronic aspects to the Synchronome Company of Westbury. The clocks were designed to run non-stop for 20 years. This system gave way to the present digital system in 1984, which uses a built-in crystal oscillator and microprocessor logic control. The complete apparatus comprises solid-state microchips, occupies no more shelf space than a small suitcase and has no moving parts at all. The BT service is assured to be accurate to five-thousandths of a second.
In 1986, BT allowed Accurist to sponsor its franchise, the first time a sponsor had been used for the service. In the latter years of this sponsorship, it cost 30 pence to call the speaking clock. Accurist announced its withdrawal from the deal and the launch of an online "British Real Time" website on 24 August 2008.
During the Cold War, the British Telecom speaking clock network was designed to be used in case of nuclear attack to broadcast messages from Strike Command at RAF High Wycombe to HANDEL units at regional police stations. From there, automatic warning sirens could be started and alerts sent to Royal Observer Corps monitoring posts and other civil defence volunteers equipped with manual warning devices. The rationale for using an existing rather than a dedicated system was that it was effectively under test at all times, rather than being activated (and possibly found to be faulty) only in the event of war. The signals to automatic sirens were sent down the wires of individual (unaware) subscribers for the same reason—a customer would report any fault as soon as it occurred, whereas a problem with a dedicated line would not be noticed until it was needed.
A version of the speaking clock was also used on recordings of proceedings at the Houses of Parliament made by the BBC Parliament Unit, partly as a time reference and partly to prevent editing. On a stereo recording, one track was used for the sound and the other for an endless recording of the speaking clock—without the pips, as these were found to cause interference.
List of voices heard on the British "BT Speaking Clock"Edit
There have been five permanent voices for the speaking clock. Temporary voices have been used on special occasions, usually with BT donating the call fees collected to charity.
- Ethel Jane Cain, first permanent voice: from July 24, 1936 to 1963.
- Pat Simmons, second permanent voice: from 1963 to April 2, 1985 (may still be heard).
- Brian Cobby, third permanent voice: from April 2, 1985 to April 2, 2007.
- Sara Mendes da Costa, fourth permanent voice: from April 2, 2007 to November 9, 2016.
- Alan Steadman, fifth permanent voice: from November 9, 2016.
- Lenny Henry, comedian, temporary voice for Comic Relief: from March 10 to March 23, 2003.
- Alicia Roland, 12-year-old schoolgirl, temporary voice for the children's charity ChildLine, from October 13 to October 20, 2003, having won a BBC TV Newsround competition and stating, before announcing the time, "It's time to listen to young people".
- Mae Whitman, temporary voice as part of a deal to promote the Disney production of Tinker Bell, for three months from 26 October 2008 until 2 February 2009.
- UK celebrities Kimberley Walsh, Cheryl Fernandez-Versini, Gary Barlow, Chris Moyles, and Fearne Cotton for Comic Relief charity: from 3 February to 23 March 2009.
- UK celebrities David Walliams, Gary Barlow, Chris Moyles, Kimberley Walsh, Fearne Cotton and a mystery voice for Sport Relief charity from 7 March to 9 April 2012.
- Clare Balding temporary voice for Comic Relief from 12 February to 15 March 2013 (with the help of a barking dog, time announced as "at the third woof".)
- Davina McCall temporary voice for Sport Relief from 27 January to 23 March 2014.
- Ian McKellen temporary voice for Comic Relief from 24 February to 13 March 2015.
- Jo Brand temporary voice for Sport Relief from 22 January to 30 March 2016.
The first automated time service in the United States began in Atlanta, Georgia in 1934 as a promotion for Tick Tock Ginger Ale. Company owner John Franklin modified Western Electric technology to create the machine that would become known as the Audichron. The Audichron Company became the chief supplier of talking clocks in the US, maintained by local businesses and, later, the regional Bell System companies.
The service became typically known as the "Time of Day" service, with the term "speaking clock" never being used. Occasionally it would be called "Time and Temperature" or simply "Time". However, the service has been phased out in most states (Nevada and Connecticut still maintain service). AT&T discontinued its California service in September 2007, citing the widespread availability of sources such as mobile phones and computers.[vague]
For all area codes in Northern California, and on the West Coast generally, the reserved exchange was 767 which was often indicated by its phoneword, POPCORN; the service was discontinued in 2007. In other locations, different telephone exchanges are or were used for the speaking clock service.
Many shortwave radio time signal services provide speaking clock services, such as WWV (voiced by John Doyle) and WWVH (voiced by Jane Barbe), operated by the National Institute of Standards and Technology from the United States of America. To avoid disruption with devices that rely on the accurate timings and placement of the service tones from the radio, the voice recording is "notched" clear of some of the tones.
The website Telephone World has examples of past and present "Time of Day" services that also include temperature and weather announcements.
- "L'horloge parlante officielle française de l'Observatoire de Paris". syrte.obspm.fr.
- "At the third stroke: George the talking clock now on atomic time". SMH. 4 April 2014. Retrieved 2017-05-01.
- Telstra Research Laboratory Internal web page
- Webb, Carolyn (2019-04-18). "At the third stroke, there will be ... no more dial-up talking clock". The Age. Retrieved 2019-07-04.
- "1194 Online Time Service Home Page". 1194online.com. Retrieved 2020-04-24.
- Silva, Kristian (2019-10-16). "When Telstra shut down the Talking Clock, one man took the time to salvage it". ABC News. Retrieved 2020-04-24.
- "Sprekende klok krijgt langer telefoonnummer - ZDNet.be". 26 December 2011.
- "China Telephones". Retrieved 2017-03-02.
- Helsingin Sanomat / Kulttuuri, 3.5.2002, Sellainen on puhelin Archived 2007-10-12 at the Wayback Machine (in Finnish)
- Turun Sanomat, 29.10.2004, Neiti Aika vaihtui herraksi Satakunnassa (in Finnish)
- Turun Sanomat, 29.10.2006, Ajalla monta näyttäjää Turussa - Oi aikoja, oi tapoja tsekata se (in Finnish)
- Laredo, Joe; Laredo, Kerry (November 25, 2001). Living and Working in Ireland: A Survival Handbook. Survival Books. ISBN 9781901130669 – via Google Books.
- "Is time up for Ireland's speaking clock service?". Belfasttelegraph – via www.belfasttelegraph.co.uk.
- The Irish Times (Friday, July 24, 1970)
- "Podcasts". Shannonside.ie. Retrieved 2021-05-20.
- "speaking clock - Aistriúchán Gaeilge ar speaking clock (An Foclóir Nua Béarla-Gaeilge)". www.focloir.ie.
- Farrell, Peter (August 27, 2018). "Eir calls time on speaking clock due to decline in use" – via www.rte.ie. Cite journal requires
- Weet u misschien ook...?, Historisch overzicht van het telecomdistrict Haarlem, J. Wurkum, 5 maart 1992
- Ik zal u doorverbinden, C.J. Wulffraat et al., in Honderd jaar telefoon, ed. J.H. Schuilenga et al., Staatsbedrijf der Posterijen, Telegrafie en Telefonie, 's-Gravenhage, 1981, p. 215
- 06 straks ook voor tijd en weerbericht, Het Vrije Volk, 16 November 1990
- Telefonische tijdmelders, Museum voor Communicatie, The Hague, Netherlands[dead link]
- "Time and Frequency Standards Services". Measurement Standards Laboratory of New Zealand. MSL. Retrieved 8 December 2017.
- Spis abonentów warszawskiej sieci telefonów Polskiej Akcyjnej Spółki Telefonicznej i rządowej warszawskiej sieci okręgowej 1938/1939. Warszawa. 1938.
- Brzoza, Czesław (1998). Kraków między wojnami. Kraków: Towarzystwo Sympatyków Historii. ISBN 83-909631-0-8.
-  (in Russian) Фокина Татьяна Алексеевна «Методические вопросы преподавания инфокоммуникаций в высшей школе» // МЕТОДИЧЕСКИЕ ВОПРОСЫ ПРЕПОДАВАНИЯ ИНФОКОММУНИКАЦИЙ В ВЫСШЕЙ ШКОЛЕ, №3-2020
-  (in Russian) Speaking clocks (официальный сайт журнала «Мои часы»)
-  (in Russian) "Speaking clocks", May(№5) 1937, Tekhnika Molodezhi, pp. 28-29
-  (in Russian) Argumenty i Fakty, 2018
- Лебедев А.Н., Боковиков А.К. "Экспериментальная психология в российской рекламе" // М.: Академия, 1995, ISBN 5-7695-0001-8. (in Russian) pp.49-50
-  Anniversary review, and reflection about the use of female and male voices , Vechernyaya Moskva (in Russian)
- "Ever wondered who does the 1026 Telkom voice?". CapeTalk. Retrieved 2020-11-28.
- The Telkom Voice, retrieved 2020-11-28
- "Служба точного времени 737-60-60".
- Wainwright, Martin (24 August 2008). "Speaking clock sponsor says it's time for change". The Guardian. Retrieved 20 October 2008.
- "BT speaking clock is no more on Virgin Media and T-Mobile! - Cable Forum". Cable Forum.
- Speaking Clock: Why are people still dialling for the time?
- UK Retail Price Index inflation figures are based on data from Clark, Gregory (2017). "The Annual RPI and Average Earnings for Britain, 1209 to Present (New Series)". MeasuringWorth. Retrieved 2 December 2021.
- Recording the first speaking clock, 1936 Retrieved on 20 October 2008
- "The Speaking Clock.BT price increase. MoneySavingExpert.com Forums". forums.moneysavingexpert.com.
- UKWMO early warning system Retrieved on 20 October 2008
- BBC News: Speaking Clock gets a new voice Retrieved on 20 October 2008
- "Dundee man is new voice of BT speaking clock". BBC. 9 November 2016. Retrieved 1 January 2017.
- "Speaking Clock Alan Steadman says Dundee still has time for the city's dialect". The Courier.co.uk. 29 December 2016. Retrieved 1 January 2017.
- "I am the new speaking clock voice". BBC News. 2003-10-13. Retrieved 2010-05-23.
- "Tinker Bell Voices Speaking Clock". BBC News. 2008-10-24. Retrieved 2010-01-04.
- BT provides celebrity climb sponsorship, Marketing Week, January 16, 2009
- "Channel 4 News - Latest UK & World News | Videos | Special Reports - Channel 4 News". Channel4.com. Retrieved 2013-11-13.
- "BT news releases". Btplc.com. Retrieved 2013-11-13.
- "Sport Relief 2020 | Comic Relief". www.comicrelief.com. Retrieved 2021-05-20.
- "Error". www.btplc.com.
- "Davina's 7 day challenge". BT.com.
- Gamester-Newton, Becky (13 March 2015). "Sir Ian McKellen unveiled as voice of Speaking Clock". BT. Retrieved 2 March 2016.
- "Sport Relief: Jo Brand is new voice of BT Speaking Clock". BT.com.
- "EYE on Kansas Online Magazine". www.eyeonkansas.org.
- Lazarus, David (August 29, 2007). "Time of day calling it quits at AT&T". Los Angeles Times. Retrieved July 22, 2011.
- LaFrance, Adrienne (2016-06-22). "Remember When You Could Call the Time? You still can, and thousands of people do it every day". The Atlantic. Retrieved 2016-06-26.
- "Time/Temperature/Weather Forecast Recordings". Telephone World. January 13, 2021. Retrieved January 14, 2021.
- Photograph of the Speaking clock announcer module (ZBA4264) built in 1955
- Website about the history of speaking clocks
- (in Polish)& http://www.audiovis.nac.gov.pl/obraz/88783/ - Polish speaking clock device from 1936
- "The Post Office Speaking Clock in Great Britain" - Nature, Volume 139, pp 892–893, published: 22 May 1937 (downloadable pdf)