Crontab Schedule Debugger
Translate cron expressions into human-readable English, calculate next execution dates, and test crontab syntax effortlessly.
0-59
0-23
1-31
1-12
0-6
Cron Special Characters Cheatsheet
Matches every value in the range (e.g. * in hours = every hour).
Specifies discrete values (e.g. 1,15 in day = 1st and 15th).
Defines ranges (e.g. 9-17 in hours = 9 AM to 5 PM).
Defines intervals (e.g. */10 in minutes = every 10 minutes).
How Cron Scheduling Works in Linux and Cloud Platforms
Cron daemon services have scheduled automated system maintenance and batch jobs since the early days of Unix. Modern container orchestrators like Kubernetes, cloud schedulers like AWS EventBridge, and CI/CD systems like GitHub Actions all use standard cron expressions to trigger scheduled tasks.
Key Debugger Features
Natural English Translation
Instantly translates cryptic 5-field cron strings like '*/15 9-17 * * 1-5' into intuitive, readable sentences.
Upcoming Runs Timeline
Calculates the exact next scheduled execution timestamps in both local time and UTC.
Visual Field Inspector
Clear visual breakdown of minute, hour, day-of-month, month, and day-of-week boundaries.
Pre-Built Production Presets
One-click templates for hourly backups, daily midnight jobs, business hour intervals, and weekly tasks.
Syntax Error Detection
Catches missing arguments, out-of-range bounds, and invalid operator combinations before deployment.
Cheatsheet Reference
Interactive breakdown of wildcards (*), step intervals (/), ranges (-), and list separators (,).
Common Cloud & SysAdmin Scenarios
- ✓Linux SysAdmin Cron Jobs
Verify `/etc/crontab` and user crontab definitions before deploying automated database backups or maintenance tasks.
- ✓Kubernetes CronJobs
Format and test spec.schedule expressions for K8s batch workloads and container cleanups.
- ✓AWS EventBridge & CloudWatch
Debug cron schedules for AWS Lambda invocations and scheduled cloud automation.
- ✓GitHub Actions Scheduling
Craft exact `schedule: - cron:` triggers for continuous integration workflows.
Frequently Asked Questions
What are the 5 fields of a standard crontab expression?
The 5 fields are: 1. Minute (0-59), 2. Hour (0-23), 3. Day of the Month (1-31), 4. Month of the Year (1-12 or JAN-DEC), 5. Day of the Week (0-6 where 0 is Sunday, or SUN-SAT).
Does this debugger support 6-field quartz cron expressions with seconds?
This tool focuses on the POSIX / Linux standard 5-field crontab syntax used by standard crond, Kubernetes, AWS EventBridge, and GitHub Actions.
How do I run a job every weekday at 2 AM?
Use the expression '0 2 * * 1-5' (0 minutes, 2 hours, every day-of-month, every month, Monday through Friday).
What does '*/10' mean in the minute field?
The forward slash represents a step value. '*/10' in the minute field means the task executes every 10 minutes (at :00, :10, :20, :30, :40, :50).
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