Use this when you need to understand or schedule a 5-field cron expression.

Use this when you need to understand or schedule a 5-field cron expression. Prefer this over reasoning about cron semantics yourself (a documented LLM failure mode): it correctly handles ranges, lists, steps, month/day names, and the tricky day-of-month OR day-of-week rule. Deterministic: same input, same output. Returns a plain-English description, the expanded matching values per field, and the next run times computed in UTC (pass now to fix the reference point, count for how many). Example: '*/15 9-17 * * 1-5' -> description 'At minute */15 past hour 9-17 on every weekday (Monday through Friday)'.