24 hour answering service

In general, a night service is any service that operates at night, such as a night-time train service or a 24-hour telephone support service.

Night service in particular is also a feature of private branch exchanges whereby for a set period during the day (usually those hours outside of normal office or work hours, when normal operator services are not provided) incoming calls are automatically redirected by the switchboard to particular telephones or other equipment (such as an answering machine, a voice mail system, or the duty station of a night watchman).

References