Good point, thanks for bringing up that use case.
I hadn't considered users who keep the same Slackware installation across hardware upgrades by migrating it with rsync. I changed the implementation to use the installation time of the aaa_base package instead of the root filesystem creation time, so the reported age now survives those migrations while keeping the implementation simple.
Thanks for the suggestion!
CC: LoneStar (nprofile…ckvg)