Cron Parser — Explain Any Crontab Expression
Parse any cron expression into plain English and preview its next five run times instantly — debug crontab schedules with confidence. Free, client-side.
🔒 100% Client-Side Processing
Your data is processed entirely in your browser and never transmitted to any server.
minute hour day-of-month month day-of-week
Common Use Cases
Verifying a schedule before deploy
Confirm your crontab entry, Kubernetes CronJob, or GitHub Actions schedule fires when you intend — the next-5-runs preview catches misplaced fields before they cost a missed nightly job.
Decoding inherited crontabs
Translate the cryptic entries in a server you just took over into plain English without mentally parsing five fields.
Learning cron syntax
Experiment with steps, ranges, and day-of-week names and instantly see the effect — including the notorious day-of-month OR day-of-week rule.
Frequently Asked Questions
- What do the five cron fields mean?
- In order: minute (0–59), hour (0–23), day of month (1–31), month (1–12 or JAN–DEC), and day of week (0–6 or SUN–SAT, with 7 also meaning Sunday). An asterisk (*) means "every value" for that field.
- What does */5 or 9-17 mean in a cron expression?
- */5 is a step — "every 5th value", so */5 in the minute field fires at :00, :05, :10 and so on. 9-17 is a range — every value from 9 through 17. They combine: 9-17/2 means every 2 hours from 9 to 17.
- How do day-of-month and day-of-week interact?
- A classic cron gotcha: when BOTH fields are restricted (neither is *), standard cron fires when EITHER matches. So "0 0 13 * FRI" runs on the 13th of every month AND every Friday — not only on Friday the 13th. This parser follows that standard behavior.
- Does this work with AWS EventBridge or CloudWatch cron expressions?
- Not directly — AWS uses a non-standard 6-field format (minute hour day-of-month month day-of-week year) and, unlike standard cron, requires exactly one of day-of-month or day-of-week to be a "?" rather than allowing both to be restricted. This parser expects the standard 5-field Unix/Linux syntax; drop the trailing year field and adjust the day fields before pasting an AWS expression here.
- Does this work for cron jobs in Python, Node.js, or CI/CD pipelines?
- Yes. Python's croniter and APScheduler, Node's node-cron, GitHub Actions' schedule trigger, GitLab CI schedules, and Kubernetes CronJobs all use the same standard 5-field cron syntax this parser handles — only AWS EventBridge/CloudWatch and Quartz (used by some Java schedulers) use non-standard field counts.
- Is my data private when I use this tool?
- Yes. This tool runs entirely in your browser using client-side JavaScript — nothing you type is transmitted to, logged by, or stored on any server. You can safely process confidential text, tokens, or code.