crontab

Cron is a time-based scheduling service in Linux / Unix-like computer operating systems.

   1 crontab -e # edit cron for current user
   2 crontab -l # list cron for current user
   3 

Every ten minutes

*/10 * * * * /path/to/command

Every hour

0 * * * * /path/to/command

Every 2 hours

0 */2 * * * /path/to/command

Once a day at midnight

0 0 * * * /path/to/command

Once a day at eight am

0 8 * * * /path/to/command

Annotations

# Order of crontab fields
# minute        hour    mday    month   wday    command

string         meaning
------         -------
@reboot        Run once, at startup.
@yearly        Run once a year, "0 0 1 1 *".
@annually      (same as @yearly)
@monthly       Run once a month, "0 0 1 * *".
@weekly        Run once a week, "0 0 * * 0".
@daily         Run once a day, "0 0 * * *".
@midnight      (same as @daily)
@hourly        Run once an hour, "0 * * * *".