The Greenwich Time Signal (GTS), popularly known as "The Pips", is a series of up to six short tones broadcast at one-second intervals by many BBC Radio stations. The pips were introduced in 1924 and have been generated by BBC to mark the precise start of each hour. Their utility in calibration is diminishing as digital broadcasting entails time lags. Other radios all around the world also created their own beep sequences, in intervalos from 15 minutes, 30 minutes or each full hour.Now available on your Androidâ„¢ phone!