> does anything actually use this field? Systemd in a way does. One of the systemd-tmpfiles entry option is to clean up unused files after some time (it ships

> does anything actually use this field? Systemd in a way does. One of the systemd-tmpfiles entry option is to clean up unused files after some time (it ships defaults for /tmp/ after 10 days and /var/tmp/ after 30 days) and for this it checks atime, mtime and ctime to determin if it should delete the file (I think you can also take a flock on the file to prevent it from being deleted as well)