Until the 1990s, many channels/stations made use of on-screen clocks to introduce certain programmes (mainly news and live event programmes). Until the 1980s, the clocks were mechanical devices. In 1980, the BBC was the first UK broadcaster to introduce an electronically generated clock (on BBC Two). Other channels/stations soon followed the BBC’s lead. Many broadcasters phased out the use of on-screen clocks during the 1990s. The BBC discontinued the use of on-air clocks in 2002. S4C was one of the last UK channels to drop the clock device – at the end of 2006.
The clock device should not be confused with the countdown device used within Schools continuity on BBC One, ITV and Channel 4/S4C.