Area broadcast shift

In telecommunication, area broadcast shift is the changing from listening to transmissions intended for one broadcast area to listening to transmissions intended for another broadcast area.

Note 1: An area broadcast shift may occur when a ship or aircraft crosses the boundary between listening areas.

Note 2: Shift times, on the date a ship or aircraft is expected to pass into another area, must be strictly observed or the ship or aircraft will miss messages intended for it. Synonym radio watch shift.

Source: from Federal Standard 1037C