This is sort of a continuation to our first guide regarding reserve auctions. If you choose to sell at 'No Reserve', there are certain times when auctions end, which are far better than others. As a famous saying goes, 'you can't be everything to everybody', so let's concentrate on the US market for now.
The key for a successful No-Reserve auction is that its last half-hour falls during the time when most people are in front of their computers (with the exception of savvy buyers who use automated programs to place proxy bids)
So, certain days are bad every year - Superbowl Sunday, Christmas Eve/Day, New Year's day (can you say 'hang-over'), Memorial Day Weekend (most people are out of town), Thanksgiving day. NOTE FOR BUYERS - if the item you're coveting ends during these times, pay close attention to it, odds are you will walk away with a steal.

Sundays are usually great during winter to have an auction end, but horrific in the warmer times - no one wants to be in front of their computer. Let's barbecue!

Saturdays are bad - unless you don't have a life like me, you're probably out doing whatever you couldn't during the week - "honey-do's", out to Yankee Candle or Pottery Barn with your wife (ugh) or hopefully golfing.

Fridays are not very good - some people have received their paychecks and can't wait to start spending, but others are calculating that bottom line and are realizing that they have spent more than they made. In addition, Friday after work is usually time to unwind and for very few people that involves watching an eBay item.

Then, there are some days which are hit or miss - any long weekend during the winter falls in that category. Dare if you will.
Now let's get down to specific times of day:

Good - between 11 a.m. and 2 p.m P.S.T. This encompasses before and after lunch on both coasts and in-between.

Great - after 7 p.m. PST. On both coasts, majority of people are home from work and are watching your item like a hawk

Bad - Mornings. Believe it or not, most people aren't 'morning people' and are not in a jolly-let's-spend-money mood before that first cup of Joe.

Baaaad - when it is between 5 p.m. and 6:30 p.m in any of the time-zones. Folks are usually stuck in rush-hour traffic and if they're bidding from their Blackberry, they're creating road hazard. Do you really want that sort of responsibility on your hands?

To summarize, best days/times for your auctions to end are Monday-Thursday in the evening, Sundays during the winter. National holidays in the fall-winter which do not involve a traditional family gathering or extensive planning are also good. If that is too complex of a formula, just stick to the sure-shots mentioned above.