Function decide_next_run 

pub fn decide_next_run(
    schedule_type: &str,
    schedule_value: &str,
    tz: Tz,
    now: DateTime<Utc>,
    run_count_after: i64,
    max_runs: Option<i64>,
    not_after: Option<DateTime<Utc>>,
    unit: f64,
) -> NextRunDecision

Decide what happens to a recurring (cron | random) task after a run. run_count_after is the count INCLUDING the run that just finished.