For the record here's what the whole thing actually is: # backup.service [Service] Type=oneshot ExecStart=/usr/local/bin/backup.sh # backup.timer [Timer] OnCalendar=--* 02:15:00 Persistent=true RandomizedDelaySec=300 [Install] WantedBy=timers.target systemctl enable --now backup.timer, and systemctl list-timers tells you when it last ran and when it runs next. Crontab can't tell you the last one.