It really depends on the item. If it stands alone, the high price/high volume times are Sat/Sun 6-8p Pacific. At this time the auctions are fast and furious. If your item doesn't stand out, it won't get the same amount of attention it would in the "off hours". If you are offering a premiere item, definitely have it end during this time. Otherwise, I find that common items get more views and bids if they end 8-10a Pacific, Monday thru Friday.
