Systemd cron units
cron.target, cron-boot.timer, cron-hourly.timer, cron-daily.timer, cron-weekly.timer, cron-monthly.timer, cron-yearly.timer, cron-boot.target, cron-hourly.target, cron-daily.target, cron-weekly.target, cron-monthly.target, cron-yearly.target, cron-boot.service, cron-hourly.service, cron-daily.service, cron-weekly.service, cron-monthly.service, cron-yearly.service
These units provide cron daemon functionality by running scripts in cron directories.
The crontabs are automaticaly translated by systemd-crontab-generator(1) .
Directory for scripts to be executed on boot.
Directory for scripts to be executed every hour.
Directory for scripts to be executed every day.
Directory for scripts to be executed every week.
Directory for scripts to be executed every month.
Directory for scripts to be executed every year.
The target unit which starts the others. This should be enabled and started to use cron functionality.
The timer units which pull the cron-schedule.target units at the appropriate time. Started and stopped by the cron.target unit. These units cannot be controlled manually.
The targets invoke all service units wanted by them, including cron-schedule.service.
The service units which run scripts in the cron directories. Started and stopped by the cron-schedule.target units. These units cannot be controlled manually. You can use journalctl(1) to view the output of scripts run from these units.
This cron replacement doesn't send any mails. The log of jobs is saved in systemd journal. Do not use with a cron daemon or anacron, otherwise scripts may be executed multiple times.
With systemd >= 209, you can execute "systemctl list-timers" to have a overview of timers and know when they will elapse.