FAQ - Why should I list an item for 365 days?
Listing an item for a 365 day auction has the advantage of a "set it and forget it" auction listing. When someone bids on the item, the listing will then start a seven day count down on the item. If the item has less than seven days left, there will be no change on the time limit.
The idea for a 365 day listing is for those who want a maximum auction time without the sellers having to manually relist an item and reassessment of optional fees, but default to seven days if there is a active bid. if you opted to have any special listings fee items, those fees would be applied again to the new listing when auto-relisted. If you listed the item with any optional fees for a 365 day auction, you would not have to worry about any fees being re-applied.
Sellers also have the option to to use a "relist until sold" option during an auction setup.