# Cron
A **cron job** is a scheduled task that runs automatically on specific times on Unix/Linux systems.
# How It Works
1. Crontab file - create a schedyle file ("crontab") that lists:
1. What command to run
2. When to run it (minute, hour, day of month, month, day of week)
2. Crond daemon - A background process checks this file every minute
3. Automatic execution - when the time matches, the command runs automatically
```bash
0 2 * * * /home/user/backup.sh
```
- `0` Run at minute 0
- `2` Run at hour 2 (2 AM)
- `*` Every day of the month
- `*` Every month
- `*` Every day of the week
- `/home/user/backup.sh` - The command to run
**Result:** Backup script runs automatically every night at 2AM
[Archived chat](https://claude.ai/share/d9df574f-b23c-4bee-afa5-13c89de376d4)