What Is a Cron Expression?
A cron expression is a string of five fields that defines a recurring schedule in Unix-like systems. Each field represents minute, hour, day of month, month, and day of week — supporting wildcards (*), ranges (1-5), lists (1,3,5), and step values (*/5).
Cron Syntax Quick Reference
| Field | Allowed Values | Special Characters |
|---|---|---|
| Minute | 0–59 | * , - / |
| Hour | 0–23 | * , - / |
| Day of Month | 1–31 | * , - / |
| Month | 1–12 | * , - / |
| Day of Week | 0–7 (0 & 7 = Sun) | * , - / |
Common Use Cases
- Scheduling backup jobs and log rotation
- Running monitoring checks at specific intervals
- Triggering CI/CD pipelines on a schedule
- Sending periodic reports and notifications
- Database maintenance and cleanup tasks