My eBay selling experiences have always put me squarely in the camp of “Sunday night is the best time to list on eBay”. For me, anyway, it seems my items have always sold best with a 7-day auction that I began (and ended) at 7PM to 7:30PM PST on Sunday. The second best day and time for me has always been Monday at 7PM to 7:30PM PST. The worst day for me has been a Tuesday, any time. I never tried Fridays because I always perceived Fridays as being a bad time for an auction to end.

The truth, of course, is that it depends on quite a number of factors, and what you're selling is a major component to what day and time is the best. For example, if you're selling office and business products, Tuesday through Thursday during the day might be the best times. Why? Because that's when people from businesses might be bidding for office supplies and equipment. And, I would have a tendency to exclude Monday and Fridays because some people might be taking a three-day weekend.

If you're selling items that school-age kids might want to bid on, then the hours immediately after the school day would be good.

If you're selling items that appeal to young adults, it's good to take a look at the television schedule. Maybe ending an auction during an episode of “Lost” isn't the best time. Nor would a Friday night be a good time.

Why is the beginning and ending time so important? It seems the bidding for items is most active when an item is just listed and several hours before the end of the auction. Of course, you'll always get bidders between those times, but it does seem that the intensity of the bidding builds up in the last hour or two. Therefore, you'd want to have your auctions end when your target audience is at home and available to follow the last-minute bidding. (Which is why Sunday night has gained a reputation for being a good time to begin and end an auction -- most people are home on Sunday nights.)

Of course, if you have items that are in high demand you don't have to worry too much about not having enough bidders. Any time would be a good time to list your items. But, for the most part, you do want to make sure you have the most bidders as possible. Be sure you check for any special television programming that would take your bidders attention away from your auction. And, if you have an auction limited to a geographic area, make you don't end an auction during a special event, like a concert in that area.

If your item is not particularly in high demand, make sure your item's not going to end when an auction for a similar item is going to end. You want all potential bidders focused on your item, not split between yours and theirs.

As with all online selling, research is the key to a profitable outcome.