I just tested this on ebay...went to advanced search, checked off completed listings, put in "beanie baby" to search for as I know there would be many listings, and hit search. The oldest listing was Oct 24 which isn't even 30 days. Something isn't right.
Hmmm...from an ebay page..."Completed listings are listings that have ended within the last 15 days, whether or not the item sold." Supposedly you must go into your "my ebay account page" and set the default to 60 days but I do not see anything in there to change this setting.