The time spent on standby; (Telecommunications) the maximum time for which a mobile phone with a fully charged battery can remain in standby mode if calls are neither received nor made.
Origin
1930s.
Definition of standby time in US English:
standby time
noun
The time spent on standby; (Telecommunications) the maximum time for which a mobile phone with a fully charged battery can remain in standby mode if calls are neither received nor made.