Function finished 

pub fn finished(
    tasks: &[Task],
    sessions: &[Session],
    kind_of: &dyn Fn(&Task) -> &'static str,
    zone: &TimeZone,
) -> Vec<Finished>

Each finished task with an estimate and time spent: its log ratio, all its sessions summed (TE14); the first estimate, else the current one (a task estimated before the first was kept). Dropped tasks never count.