Use Time Machine on a Remote Mac

I can’t remember if it is an option in the columns, and I can’t check it because I’m not on my Mac, but look for last used date. If it’s not a column option, you may have to look at the metadata for the last used date.

if it’s only available in the search criteria, you might be able to set up a smart folder that shows you sparse bundles that have not been used in the last X number of days.

The column name me may be last opened, but the Matt metadata is last used.

Most of the metadata is not visible in the GUI except as criteria for a Smart Folder (search).

You can view it all with the metadata list (mdls) command in Terminal.

I think mdls would only be useful to see if that info is updated/correct.

If it is, you could make a Smart Folder to find the ones not opened recently.

Instead of looking at the date, you’ll get a list of devices that meet your overdue criteria.

Sorry, but I just got time to check my network backups and the disk image date last opened is not updated with the backups, so that won't work. I didn't see anything in the metadata that would be useful.

I generally cannot mount my Time Machine disk images, so I don't think that would be possible, either.