February 5: BBC pips began broadcasting (1924)

The pips in time interval

The hourly time signal known as Greenwich Time Signal, more commonly known as the pips or BBC pips, began broadcasting by BBC radio stations in 1924. It is a series of six short tones broadcast at one-second intervals, which occur on the 5 seconds leading up to the hour and on the hour itself, to mark the precise start of each hour. The pips are from an atomic clock in the basement of the BBC's headquarters Broadcasting House synchronized with the National Physical Laboratory's Time from NPL (UK's time reference) and GPS.