Greenwich Time Signal Greenwich Time Signal 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 stations. The pips were introduced in 1924 and have been generated by the BBC since 1990 to mark the precise start of each hour. Their utility in calibration is diminishing as digital broadcasting entails time lags. There are six pips (short beeps) in total, which occur on each of the 5 seconds leading up to the hour and on the hour itself. Each pip is a 1 kHz tone (about halfway between
Greenwich Time Signal pips were of equal length and confusion arose as to which was the final pip, hence the last pip was of extended length. The pips are available to BBC radio stations every 15 minutes but except in rare cases, they are only broadcast on the hour, usually before news bulletins or news programmes. On BBC Radio 4, the pips are broadcast every hour except at 18:00 and 00:00 and at 22:00 on Sundays (at the start of the Westminster Hour) when they are replaced by the Westminster chimes of Big Ben at the Palace of Westminster. No time signal is