[Unit]
Description=Daily Backup Timer for %i
Requires=service-backup@%i.service

[Timer]
# Run daily at 3:00 AM
OnCalendar=*-*-* 03:00:00
# If system was down during scheduled time, run on next boot
Persistent=true
# Add randomization to avoid conflicts with other services
RandomizedDelaySec=300

[Install]
WantedBy=timers.target