Speaking Clock

A speaking clock service is a recorded or simulated human voice service, usually accessed by telephone, that gives the correct time. The first telephone speaking clock service was introduced in France, in association with the Paris Observatory on 14 February 1933.

The format of the service is somewhat similar to those in radio time signal services. Every ten seconds, a voice announces "At the third stroke, the time from BT will be twelve forty-six and ten seconds...", with three beeps following. At the third beep, the time at that point is the time announced previously. Some countries have sponsored time announcements and include that in the message.

The services are traditionally useful in verifying whether time keeping equipment is functioning correctly in its automatic compensation to or from DST, or when clocks noticeably being to "lose time". Other applications are if a cell phone's battery dies, wrist watch malfunctions, or to help time keepers adjust or synchronize many time keeping devices in an area, which might otherwise all end up on different deviations of time.