Cron Parser
Parse cron expressions into plain English and preview the next 10 run times. Generate cron strings from a form.
Runs entirely in your browser. Nothing is sent to our servers.
About cron
Cron is the standard Unix job scheduler. A cron expression is a 5-field schedule that tells the daemon when to run a command. The fields, from left to right, are minute (0–59), hour (0–23), day of month (1–31), month (1–12), and day of week (0–6, where 0 = Sunday).
Field syntax
*— every value in the field's range.a-b— a contiguous range, inclusive (1-5= Mon-Fri).a,b,c— explicit list (0,15,30,45).*/n— every nth value starting from 0 (*/15in minute = 0, 15, 30, 45).a-b/n— every nth value in a range.
Day-of-month and day-of-week
When both day-of-month and day-of-week are non-*, classic cron
runs the job if either matches. This trips people up
regularly. For "every Monday in March" use 0 0 * 3 1 — not
0 0 1-31 3 1, which would run every day in March plus every
Monday.
Frequently asked questions
- Does this support 6-field cron (with seconds)?
- No — this tool uses the standard 5-field POSIX cron format. Quartz and some schedulers (like Jenkins) use 6 or 7 fields with seconds and years; those aren't supported here.
- What's the difference between <code>0 */2 * * *</code> and <code>0 0,2,4,6,8,10,12,14,16,18,20,22 * * *</code>?
- Nothing — they're equivalent. The first is shorthand. Some people prefer the explicit form for clarity, especially when starting from a non-zero offset like
0 2-22/4 * * *. - Does this account for daylight saving time?
- The preview uses your selected timezone, including its DST transitions. Real-world cron daemons differ in how they handle the missing/duplicated hours — vixie-cron skips missing hours, runs duplicated ones once. systemd timers can be configured either way.
- Why is my <code>@reboot</code> not shown here?
@rebootisn't a schedule — it runs once when the system starts up. There's nothing to preview for it.
Last updated: May 17, 2026