Select Menu > Log > Call duration to view the duration for the last call, total duration for the received calls, the dialled calls and the all calls.
To clear the call duration timers, select Options > Clear timers. For this you need the lock code (default lock code 12345 ).
To change timeperiod to keep log events in the device memory select Options > Settings > Log duration. Maximum timeperiod is 30 days.
Note: The actual invoice for calls and services from your service provider may vary, depending on network features, rounding off for billing, taxes, and so forth.