Cron Expression Builder & Schedule Explainer
Generate and translate 5-part crontab expressions into plain English with next execution dates simulation and syntax cheatsheet.
Next 5 Simulated Execution Times (UTC)
Standard 5-Field Crontab Syntax Guide
*
Any / Every value
,
Value list separator (e.g. 1,15,30)
-
Range of values (e.g. 1-5 for Mon–Fri)
/
Step intervals (e.g. */10 for every 10)
About this tool
How to use it
- Select your desired schedule parameters using the five dropdown columns (Minute, Hour, Day of Month, Month, Day of Week).
- Alternatively, paste any standard 5-part crontab expression directly into the expression input box.
- Read the instant plain English translation explaining exactly when your scheduled task will trigger.
- Inspect the next 5 simulated execution timestamps (UTC) and copy your verified cron string with 1 click.
Why it matters
Misconfigured crontabs lead to runaway automated scripts, database backups triggering during peak daytime traffic, or missing scheduled reports entirely. Testing expressions with real-time human explanations and execution timestamp simulators eliminates crontab syntax errors.
When to use it
Use this tool when setting up Linux crontab jobs, AWS EventBridge rules, GitHub Actions scheduled workflows, or Kubernetes CronJobs.
Good to know
Standard POSIX cron consists of 5 fields: (1) Minute 0-59, (2) Hour 0-23, (3) Day of Month 1-31, (4) Month 1-12, (5) Day of Week 0-6 (where 0 is Sunday).
Common questions
What does */5 mean in a cron expression?
The slash operator (/) denotes a step interval. When placed in the first field (*/5 * * * *), it triggers the task every 5 minutes (at minute 0, 5, 10, 15, etc.).
How do I run a job Monday through Friday at 9 AM?
Use the expression '0 9 * * 1-5'. The hyphen (-) represents an inclusive range: 0 is the minute, 9 is 9:00 AM, the asterisks mean every day and month, and 1-5 covers Monday through Friday.
Is Sunday 0 or 7 in cron?
In standard Linux cron, Sunday can be represented as either 0 or 7. In standard POSIX syntax, 0 is Sunday and 6 is Saturday.
Does this tool run purely in the browser?
Yes. All cron parsing, human-readable translations, and execution date simulations are performed 100% locally in your web browser with zero server data tracking.