Foobar2000:Components 0.9/File Date (foo filedate)
From Hydrogenaudio Knowledgebase
Right-click and add a file date tag (added, created, modified or accessed). Go to config page and choose a date format first. It's best if you check "Block tag update operations" in Database, so as to have the tag only in db, because if this option is unchecked, you'll actually modify the file, so the date tag (modified or accessed) would not be valid.