fstrim doesn't appear to have any timers, how do I make sure it works?

"The util-linux package provides fstrim.service and fstrim.timer systemd unit files. Enabling the timer will activate the service weekly. The service executes fstrim(8) on all mounted filesystems on devices that support the discard operation." From: https://wiki.archlinux.org/title/Solid_state_drive I wanted to make sure it runs weekly, as I've read it shouldn't run too often, and not too rarely. However, it doesn't appear to have any timers: # systemctl list-timers |grep fstrim # cat /etc/systemd/system/fstrim.timer cat: /etc/systemd/system/fstrim.timer: No such file or directory The fstrim.service file itself is: # systemctl cat fstrim.service # /usr/lib/systemd/system/fstrim.service [Unit] Description=Discard unused blocks on filesystems from /etc/fstab Documentation=man:fstrim(8) ConditionVirtualization=!container [Service] Type=oneshot ExecStart=/usr/bin/fstrim --listed-in /etc/fstab:/proc/self/mountinfo --verbose --quiet-unsupported PrivateDevices=no PrivateNetwork=yes PrivateUsers=no ProtectKernelTunables=yes ProtectKernelModules=yes ProtectControlGroups=yes MemoryDenyWriteExecute=yes SystemCallFilter=@default @file-system @basic-io @system-service Where is the weekly basis specified? How do I make sure it runs weekly, or at all?