Function skip_missed_run 

pub fn skip_missed_run(
    config: &Config,
    job: &CronJob,
    now: DateTime<Utc>,
) -> Result<()>

Advance next_run of an overdue recurring job to its next future occurrence without executing the missed run. For one-shot At jobs there is no future occurrence, so the job is disabled and its last status is recorded as skipped.

Called at scheduler startup when catch_up_on_startup is disabled, so the subsequent normal polling loop won’t pick up jobs whose next_run is still in the past.