Build cron job schedules visually. Understand cron syntax with human-readable descriptions and see next execution times.
| Field | Values | Specials |
|---|---|---|
| Minute | 0-59 | * , - / |
| Hour | 0-23 | * , - / |
| Day of Month | 1-31 | * , - / |
| Month | 1-12 | * , - / |
| Day of Week | 0-7 (0,7=Sun) | * , - / |
Cron is a time-based job scheduler in Unix/Linux systems. It allows you to schedule commands or scripts to run automatically at specific times, dates, or intervals. Cron expressions define the schedule using five fields: minute, hour, day of month, month, and day of week.
| Character | Meaning | Example |
|---|---|---|
| * | Every value | * in minute = every minute |
| , | List separator | 1,15 in day = 1st and 15th |
| - | Range | 1-5 in DOW = Mon to Fri |
| / | Step values | */15 in minute = every 15 min |
Run crontab -e to edit your cron file, then add a line with the cron expression
followed by the command. For example: 0 2 * * * /usr/bin/backup.sh runs backup.sh
at 2:00 AM daily.