Cron Expression Parser
0 9 * * *At minute 0, past hour 9
| Field | Allowed Values | Special Characters |
|---|---|---|
| Minute | 0-59 | * , - / |
| Hour | 0-23 | * , - / |
| Day of Month | 1-31 | * , - / |
| Month | 1-12 | * , - / |
| Day of Week | 0-6 (Sun=0) | * , - / |
Parse and explain cron expressions in plain English. See the next 10 scheduled run times. Supports standard 5-field cron syntax.
How to Use Cron Expression Parser
- Enter a 5-field cron expression (minute hour day month weekday).
- See the plain English description of the schedule instantly.
- View the next 10 scheduled run times calculated from now.
- Use the example buttons to try common cron patterns.
What is a Cron Expression?
A cron expression is a string of five space-separated fields that defines a recurring schedule for automated tasks. Originating from Unix systems in the 1970s, cron has become the universal standard for job scheduling across operating systems, cloud platforms, and CI/CD pipelines. Each field represents a time unit: minute (0-59), hour (0-23), day of month (1-31), month (1-12), and day of week (0-6, where 0 is Sunday). This tool parses any valid cron expression into a plain English description and calculates upcoming execution times.
How Cron Syntax Works
Each field supports several types of values. An asterisk (*) means "every" value for that field. A specific number sets an exact value (e.g., 30 in the minute field means minute 30). A slash (/) defines intervals: */5 means every 5 units. A hyphen (-) defines ranges: 1-5 means values 1 through 5. A comma separates individual values: 1,3,5 means only those specific values. These can be combined for complex schedules like 0 9-17 * * 1-5 (every hour from 9 AM to 5 PM, Monday through Friday).
Common Use Cases
- Scheduling automated database backups at off-peak hours
- Running CI/CD pipelines on a nightly or weekly basis
- Sending scheduled email reports or notifications
- Triggering periodic data processing and ETL jobs
- Configuring Kubernetes CronJobs and cloud scheduler tasks
- Verifying cron expressions before deploying to production
Common Pitfalls with Cron
The most frequent mistake is confusing month and day-of-week numbering. Months are 1-12, but day-of-week varies: standard cron uses 0-6 (Sunday to Saturday), while some systems use 1-7. Another common issue is timezone confusion. Cron jobs run in the server's configured timezone, not necessarily UTC. If your server is in US Eastern time, a job scheduled for 0 0 * * * runs at midnight Eastern, not midnight UTC. Always verify the timezone of your cron daemon. Daylight Saving Time can also cause jobs to run twice or be skipped entirely when clocks change.
To build cron expressions visually, try the Crontab Generator. For working with timestamps, use the Unix Timestamp Converter or the Timezone Converter.