Greenwich Time Signal 19:00. By 19:45 the same day the power supply was repaired and the 20:00 pips were broadcast as normal. Many radio broadcasters around the world use the Greenwich Time Signal as a means to mark the start of the hour. The pips are used in both 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. Greenwich Time Signal The Greenwich Time Signal (GTS), popularly known as the pips, is a series of six short tones broadcast at one-second
Time signal a common hazard, the emergency sirens are tested regularly at a specified time (say, noon each Saturday); while not primarily intended to mark the time, local people often check their watches when they hear this signal. In many non-seafaring communities, loud factory whistles served as public time signals before radio made them obsolete. Sometimes, the tradition of a factory whistle becomes so deeply entrenched in a community that the whistle is maintained long after its original function as a time keeper became obsolete. For example the University of Iowa's power plant whistle has been reinstated several times by popular demand