Solution:

Create timer unit:

cat > /etc/systemd/system/backup-now.timer < < 'EOF'

[Unit]

Description=Daily backup timer

[Timer]

OnCalendar=*-*-* 02:00:00

Persistent=true

[Install]

WantedBy=timers.target

EOF

Enable it:

systemctl daemon-reload

systemctl enable --now backup-now.timer

systemctl list-timers --all | grep backup-now

Detailed Explanation:

OnCalendar=*-*-* 02:00:00 means daily at 02:00.

Persistent=true runs missed jobs after boot if the system was off.

timers.target is the normal target for timer units.

RHEL 10 documentation includes systemd timer units as a standard scheduling mechanism. ( Red Hat Documentation )