Cron Expression Parser
| Field | Value | Meaning |
|---|---|---|
| minute | * | every minute |
| hour | * | every hour |
| day | * | every day |
| month | * | every month |
| weekday | * | every weekday |
How to Use
- Enter a standard 5-field cron expression (minute, hour, day, month, weekday).
- The tool instantly shows a human-readable description of the schedule.
- Each field is broken down with its meaning.
- The next 5 scheduled run times are displayed.
Cron Syntax
- * (asterisk): Every possible value for that field.
- 5: A specific value (e.g., minute 5, hour 5).
- 1-5: A range of values (e.g., Monday through Friday).
- */15: Step values (e.g., every 15 minutes).
- 1,15: A list of values (e.g., the 1st and 15th).
Cron Fields
- Field 1: Minute (0-59)
- Field 2: Hour (0-23)
- Field 3: Day of Month (1-31)
- Field 4: Month (1-12)
- Field 5: Day of Week (0-7, where 0 and 7 are Sunday)
What is a Cron Expression?
A cron expression is a string of five fields that defines a schedule for recurring tasks on Unix-like systems. Originally part of the cron daemon in Unix, the format has been adopted by virtually every scheduling system including cloud services (AWS CloudWatch, Google Cloud Scheduler), CI/CD platforms (GitHub Actions, GitLab CI), and application frameworks. Each field specifies when the task should run: minute, hour, day of month, month, and day of week.
Use Cases
- CI/CD pipelines: Schedule nightly builds, weekly dependency updates, or periodic security scans in your CI/CD system.
- Database backups: Configure automatic backups at off-peak hours to minimize impact on production workloads.
- Monitoring and alerts: Set up health checks, log rotation, or report generation at regular intervals.
- System maintenance: Schedule cache clearing, temporary file cleanup, or certificate renewal tasks.
- Business automation: Run periodic data exports, email digests, or billing calculations on a fixed schedule.
Privacy
All parsing happens in your browser. No data is sent to any server.
FAQ
How many fields does this tool support?
It supports the standard 5-field cron expression (minute, hour, day, month, weekday). The 6-field form with a seconds field and AWS's variant with a year field are not supported, and anything other than 5 fields shows an error.
Is the cron expression I enter sent to a server?
No. Parsing the expression, generating the description, and computing the next run times all happen in your browser. Your expression is never sent to a server.
What syntax does it accept?
It handles * (every value), specific values (5), ranges (1-5), steps (*/15), and lists (1,15). If a field is out of range or non-numeric, the tool shows a specific error message explaining what went wrong.
How many upcoming runs are shown?
For a valid expression, the tool shows the next 5 scheduled run times. It also breaks down each field with its meaning so you can verify the schedule at a glance.
Are both 0 and 7 Sunday in the weekday field?
Yes. The weekday field ranges from 0-7, where both 0 and 7 represent Sunday, matching standard Unix cron behavior.