call time
/ˈkɔːl tʌɪm/noun
1The time at which a call is made.
2The duration of a call; (Telecommunications ) time spent, or available for, making a telephone call; specifically (on a mobile phone) a quantity of time available for making pre-paid calls; (also) the total amount of time available for calls from a mobile phone with a fully-charged battery.
Origin
Late 19th century; earliest use found in Political Science Quarterly. From call + time interjection conj..