CompTIA Linux+ XK0-006 (V8) Practice Question

The pattern *-*-* 03:15:00 in an OnCalendar= expression matches every day of every month at 03:15, providing the required daily schedule. Setting Persistent=true tells systemd to store the time of the last successful trigger and, when the timer is (re)activated, to run the associated service immediately if any scheduled run was missed-exactly the desired catch-up behaviour after an outage.

The other choices all fail in at least one respect:

• OnCalendar=daily schedules the job at 00:00, and WakeSystem=true only wakes the system from suspend; it does not make up for missed runs.
• OnBootSec=3h15m triggers once per boot, not at a fixed wall-clock time, and RemainAfterElapse= affects only the timer's state tracking.
• OnCalendar=Mon..Sun 03:15:00 fires at the correct time but, without Persistent=true, it waits until the next 03:15 instead of catching up after downtime.