Cron Explainer

How it works

• Everything runs client-side: the expression is parsed and the next run times are computed right in your browser — nothing is uploaded.
• The plain-English explanation is generated by the cronstrue library; the field breakdown and "next run times" are computed independently by this page from the same expression.
• Linux mode expects 5 fields (minute, hour, day-of-month, month, day-of-week). Quartz mode expects 6 fields (adds seconds at the front) or 7 (adds a year at the end).
• Supports wildcards (*), steps (*/5), ranges (1-5), lists (1,3,5), combinations of these, and month/weekday names (MON, JAN).
• Quartz-only special characters L, W, and # (last day, weekday-nearest, nth weekday) are recognized by the explanation but not resolved by the next-run calculator — the run list is hidden when one of these is used.
• If day-of-month and day-of-week are both restricted (neither is * or ?), standard cron semantics apply: a date matches if it satisfies either field.