Cool idea, and a good use for systemd timers. A few things: 1) your home directory (/home/qertoip/) is hardcoded in the .service file, 2) this assume you're us

Cool idea, and a good use for systemd timers. A few things: 1) your home directory (/home/qertoip/) is hardcoded in the .service file, 2) this assume you're using cinnamon-screensaver, for portability you should probably have a configuration var for "lock command" or similar, and 3) you should avoid the symlink setup for /usr/lib/systemd/system/, user .service and .timer files should be put in (or symlinked into) /etc/systemd/system (see man 5 systemd.unit).