Iterating the Next N Occurrences

Many tools want to preview a cron schedule: "what are the next 5 firings?" This is just next_run repeated, feeding each output back as the new after:

Beware infinite loops with NEVER results. Cap iterations and bail early.

This API powers UIs like crontab.guru and lets your scheduler plan ahead: materialize the next 1000 firings into the priority queue and only re-plan when the head changes.