Systemd timer syntax
From wikinotes
Timer files can be used to control when a systemd service of the same name runs.
It is similar to cron.
Documentation
official docs https://www.freedesktop.org/software/systemd/man/systemd.timer.html
Example
Vdirsyncer is a good example.
# /etc/systemd/system/vdirsyncer.timer [Unit] Description=Synchronize vdirs [Timer] OnBootSec=5m # run 5m after boot OnUnitActiveSec=15m # also run every 15m AccuracySec=5m [Install] WantedBy=timers.target# /etc/systemd/system/vdirsyncer.service [Unit] Description=Synchronize calendars and contacts Documentation=https://vdirsyncer.readthedocs.org/ [Service] ExecStart=/usr/bin/vdirsyncer sync Type=oneshotsystemctl enable vdirsyncer.timer