How to import "date added"? File creation/modified time?

[flight16]

I'm trying to import a bunch of music from another program into GoneMAD.  I want to use the "Sort by date added" option for albums.  Where does Date Added get its time when sorting?  Date added to GoneMAD's library, file creation time, file modified time?  

I would like to be able to sort by file creation or file modified time because I have control over this, so I'm able to "import" my Date Added information from another library.

Does this make sense?  Is it currently possible?

[GoneMAD]

date added is when its scanned into gmmp's database