Most people will have a different idea in regards to finishing times, but for me it comes down to one thing, and that is knowing your market.
For me, when I do list on eBay, I am going after a general market mostly, nothing specific. I pick a Sunday afternoon, usually around 5.00 or 7.00pm, because this is the most likely time of the week that you will find families all together. The weekend has wound down and most people are now just relaxing, soaking up the last few hours of the weekend.
It's the perfect storm, you have everyone in the one spot, nothing much important on their mind, so they shouldn't simply forget about your listing, so in a numbers game, you have increased your odds.
You need to ask yourself if you are hitting your target market at a time like 10pm. For people working early, 10pm is probably too late, so you won't be hitting that market.
A 10pm time slot indicates to me that you are chasing a younger demographic, possibly one that isn't working and one that has a good memory and not to involved in late night television to remember your listing ending and bidding.
If that's your market, then you have it nailed, if it's not, then you may want to take a closer look at your demographic and try to target them a little better : )