Empty albums imported the correct 'Create Date', but 'Last Update' says "Jan 1, 1970"
I haven't been able to test whether this is also a problem on albums with images as I ran into a bug with the importer not correctly importing images into the albums. I've filed a support ticket, as I think that's a problem specific to my installation, but once that's resolved I will check that as well.
At the time of import, empty albums should have 'Last Update' set to their 'Create Date' value. Imported albums with photos should have 'Last Update' set to the upload date of the most recently uploaded photo to the album.