Anacron for Debian
------------------

Anacron runs transparently to the system.  In other words, you should
never be aware that anacron and not cron is actually running
cron.{daily,weekly,monthly,yearly}.

Anacron itself however is not a daemon, so it will either be called at
startup, on APM power status change, on systemd timer or by cron.
Disabling those will result in some jobs not being executed on time.

Anacron leaves messages in /var/log/syslog and /var/log/messages by
default.

By default, anacron does not run while on battery power.
Debian has added udev rules to trigger anacron when AC power is online
and offline, but you may still want to keep anacron running when
you are using battery.

If you are using SysVinit, see /etc/default/anacron to change that.

If you are using systemd and want to run anacron even when running on battery,
you should create the following file with the specified content and then call
"systemctl daemon-reload":
    /etc/systemd/system/anacron.service.d/on-ac.conf:
        [Unit]
        ConditionACPower=

 -- Boyuan Yang <[email protected]>  Sun, 11 Nov 2018 18:28:17 -0500