Due to a lack of proper housekeeping, our server has several dozen home
directories belonging to users that have long since left the company.
I'm therefore trying to find an easy way of locating directories that
haven't been used for a while and deleting them.

I've tried using NDIR:

NDIR \\server\volume\homedirs /SORT UP

.... but it doesn't work for directories, only individual files. However,
if I right-click on an individual home directory in Explorer and click
"NetWare Info", I can see the update time. Can anyone suggest of a way
of pulling this information into a file, or another way of removing home
dirs that don't belong to anyone?