crond
/etc/crontab
crontab -e
crontab -l
0 */2 2 12 5 #Every 2 hours on the hour on December second and every Friday in December
minute hour day of month mont day of week (0 and 7 is Sunday)
0 11 * * 1-5 #Every day at 11 a.m. on weekdays only
/etc/cron.d
/etc/cron.hourly
/etc/cron.daily
/etc/weekly
/etc/cron.monthly
/etc/anacrontab
atd -l 3.0 #No batch started when system load is higher than 3.0


systemd-tmpfiles
systemd-tmpfiles --clean
systemd-tmpfiles --create
man tmpfiles.d