Nokia 5165 User Manual page 50

Last call is the duration of the last call, or current call if
applicable.
All calls is the duration of all calls since the timers were last
reset.
Life timer displays the duration of all calls for the life of
your phone and cannot be reset.
Setting timers back to 0
Use Menu 3 5 4 to clear call timers. You will be required to
enter your security code.
Displaying the current call timer during calls
1 Press Menu 3 5 1.
2 Press Details.
3 Press Select.
4 Scroll to On, then press OK.
During a call, the amount of time spent in that call will be
displayed.
43