Cron Expression Parser
Explain any cron schedule in plain English with the next run times
About this tool
Paste a five-field cron expression and get it explained in plain English, with a field-by-field breakdown and — the part that catches real mistakes — the next five actual run times computed in your local timezone. "0 3 * * 1" reads back as "At 03:00, on Monday", followed by the concrete dates it will fire.
The parser supports the full standard syntax: lists (1,15), ranges (9-17), steps (*/15), month and weekday names (jan, mon), 7 as Sunday, and the @daily/@hourly macro family. It also implements the rule everyone forgets: when both day-of-month and day-of-week are restricted, the job runs when either matches, not both.
Six-field (Quartz, with seconds) expressions are detected and called out explicitly rather than silently misparsed — the most common source of "my cron is wrong" confusion when moving between Java schedulers and Unix crontab.
Frequently asked questions
- What are the five fields, in order?
- Minute (0–59), hour (0–23), day of month (1–31), month (1–12), day of week (0–6, Sunday = 0, with 7 also accepted as Sunday). Remembering the order is the eternal struggle — the breakdown panel labels each field of your expression.
- Why does "0 0 1 * 1" run more often than I expected?
- Because both day-of-month (1st) and day-of-week (Monday) are restricted, cron runs the job when EITHER matches — every 1st of the month AND every Monday. To mean "the 1st only when it is a Monday", you need script-side date checking.
- Which timezone do the next-run times use?
- Your browser's local timezone, shown alongside the results. Real crontabs run in the server's timezone (or the TZ= line in some crons) — always confirm what the target machine uses, especially across DST changes.
- Does this support seconds or years?
- No — those are Quartz (Java) extensions with 6 or 7 fields. Standard Unix cron has exactly five fields and one-minute resolution. Six-field input is detected and reported as Quartz rather than misread.