Linux

systemd

For daily user backups using systemd timers, put the following ~/.config/systemd/user/crestic@.service

[Unit]
Description=crestic %I backup

[Service]
Nice=19
IOSchedulingClass=idle
KillSignal=SIGINT
ExecStart=/usr/bin/crestic %I backup

and the following in ~/.config/systemd/user/crestic@.timer

[Unit]
Description=Daily crestic %I backup

[Timer]
OnCalendar=daily
AccuracySec=1m
RandomizedDelaySec=1h
Persistent=true

[Install]
WantedBy=timers.target

then activate the timer for your crestic preset, i.e. for home@nas

systemctl --user enable --now crestic@home@nas.timer

For system backups, put these files in /etc/systemd/system and the config in /etc/crestic/config.cfg.

Also see the Arch Linux package for a working solution including systemd timers.