1The time a call is made.
The time at which cast and crew are required to be at the theatre or on set.
3 rare The duration of a visit or call.
4Time spent on, or available for, making telephone calls; (in later use) specifically (a) time available for making prepaid or free calls, especially on a mobile phone; (b) the total amount of time available for calls when a mobile phone battery is fully charged.
Mid 19th century. From call + time.