An audible signal indicating the exact time of day, especially one broadcast by radio at certain times.
（尤指由收音机发出的表示确切时间的）报时信号
Example sentencesExamples
It was wound solemnly each Sunday morning, checked against the BBC time signal, adjusted, and the glass cover snapped gently back for another week.
The BBC first used the six pips as a broadcast time signal - in recent years the sixth pip has been elongated for emphasis.
Atomic clocks are designed to receive radiofrequency transmissions of time signals several times a day to auto-adjust the time.
These systems work by comparing time signals received from different satellites.
Every night, the clock automatically checks the radio-delivered official time signal and makes whatever adjustments are necessary to stay synchronized.