auto reboot at 9am?

ive got a surface tablet at work running nixos. it mostly is used to view security cameras.

the machine is fairly low spec and bogs itself down after a coupke days, so id like it to auto reboot at 9am. i work a late shift and often don't leave til around 2am.

i guess we don't use cron anymore? i really don't understand how the systemd timers work... the wiki doesnt really give great details...

systemd.timers."autoreboot" = {

wantedBy = [ "timers.target" ];

        timerConfig = {

      OnCalendar="*-*-* 9:00:00";                                     Unit = "autoreboot.service";

    };


  

};

systemd.services."autoreboot" = {

script = ''

        set -eu

    ${pkgs.coreutils}/run/current-system/sw/bin/reboot


  

'';

serviceConfig = {

        Type = "oneshot";

    User = "root";


  

};

};

the systemd target seems to be created, but it reports as dead when i check it...

any advice?