Scheduling Repetitive Tasks

The cron daemon examines crontab files every minute, and checks if the command in each line should be run in the current minute.

crontab

Maintain crontab files.

crontab -e

minute hour day_of_month month day_of_week command

1. minute (0 to 59)
2. hour (0 to 23)
3. day of month (1 to 31)
4. month (1 to 12, or jan, feb, etc)
5. day of week (0 to 7, 0 or 7 is Sunday, or sun, mon, etc)
6. command (or script)
7. newline