In general, a night service is any service that operates at night

Night

Night or nighttime is the period of time when the sun is below the horizon. This occurs after dusk. The opposite of night is day...

, such as a night-time public transport

Public transport

Public transport is a shared passenger transportation service which is available for use by the general public, as distinct from modes such as taxicab, car pooling or hired buses which are not shared by strangers without private arrangement.Public transport modes include buses, trolleybuses, trams...

 service or a 24-hour telephone support service.

Night service in particular is also a feature of private branch exchanges and business telephone systems, 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

Switchboard

The term switchboard, when used by itself, may refer to:*Telephone switchboard*Electric switchboard*Printed circuit board*Mixing console*In computing, Switch board...

 to particular telephones or other equipment (such as an answering machine

Answering machine

The answering machine or message machine, also known as the telephone answering machine in the UK and some Commonwealth countries) and previously known as an ansaphone, ansafone, or telephone answering device is a device for answering telephones and recording callers' messages.Unlike voicemail,...

, auto attendant, voice mail system, or the duty station of a night watchman).