Cron Parser
Parse cron expressions and view human-readable descriptions with next execution times.
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How to Use
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- 1
Enter a cron expression
Type a 5-field cron expression in the input field, or select from the presets.
- 2
View the description
The cron expression is parsed and a human-readable description is displayed.
- 3
Check execution times
The next 10 scheduled execution times are shown. Use the copy button to copy results to your clipboard.
Cron Expression
All processing runs locally in your browser via JavaScript.
Presets
About Cron Parser
Cron Parser translates standard 5-field cron expressions into plain English and shows the next 10 scheduled run times instantly. Cron syntax is notoriously easy to get wrong — a misplaced asterisk or an off-by-one in the day-of-week field can silently skip critical jobs or trigger them at 3 AM instead of midnight. Paste any expression and verify the exact schedule before it lands in a Kubernetes CronJob manifest, a GitHub Actions schedule trigger, or a crontab on your EC2 instance. Seeing the concrete next 10 execution timestamps makes it far easier to catch mistakes than staring at raw syntax alone.
Key Features
- Parse and validate standard 5-field cron expressions
- Convert to human-readable descriptions
- Show next 10 execution times
- Common pattern presets
- Copy descriptions and schedules to clipboard
Common Use Cases
- Verify a Kubernetes CronJob schedule (e.g., database backup at 2 AM UTC) before applying the manifest
- Debug a GitHub Actions scheduled workflow that isn't triggering at the expected time
- Validate crontab entries on EC2 or bare-metal servers before deploying
- Confirm that a '0 */6 * * *' expression runs every 6 hours and not every minute
- Translate a business requirement ('run every weekday at 9 AM EST') into the correct 5-field expression
- Share a human-readable schedule description with non-technical stakeholders alongside the raw cron string
Frequently Asked Questions
What cron format is supported?
Standard 5-field format (minute hour day-of-month month day-of-week). Each field supports *, numbers, ranges (N-M), lists (N,M), and steps (*/N).
Does it support seconds?
No, only the standard 5-field format is supported. Extended formats like Quartz (with seconds) are not supported.
What timezone is used for next execution times?
Times are displayed in your browser's local timezone. Note that cron daemons on servers typically run in UTC unless configured otherwise — double-check the server timezone with 'timedatectl' or by examining /etc/timezone before relying on the preview.
Is my cron expression sent to a server?
No. Parsing and next-execution calculation run locally via the cron-parser library in your browser. Expressions from internal job definitions are never transmitted.
Are "*/5 * * * *" and "0,5,10,15,20,25,30,35,40,45,50,55 * * * *" equivalent?
Yes, both run every 5 minutes. The step notation (*/5) is simply a shorthand for the explicit list. You can confirm they behave identically by comparing the next-execution previews for both expressions.
What happens if I specify both a day-of-month and a day-of-week?
In the UNIX cron standard, specifying both fields uses OR logic — the job runs when either condition is met. For example, "0 9 1 * 1" runs at 9 AM on the 1st of every month and also every Monday at 9 AM. To avoid unintended behavior, it is best to leave one of the two fields as "*".