If you think listing an item at anytime of day will make your listing equally as successful, think again. What may be convenient for you, say 4:00pm on a weekday when you're not in classes, or at work, may not be ideal for someone else. eBay's listings end on 24 hour intervals, no matter what time of day you start them on. So if you listed an item to begin at 4:00pm CST, that would be 2:00pm on the west coast (when generally people are not home on a given weekday). So if you want to discourage bidders say in California or British Columbia from bidding, I wouldn't suggest listing an item as this time.

Never use a 1-day listing unless you want to sell something that is time sensitive, such as concert tickets at the last minute for example. You also have to be an established member of the eBay community to even have the option to serve a 1-day listing. Generally, when do most people have the greatest amount of spare time? On the weekends. Choose to list your items based upon the schedule of society.

Generally, the most successful listing times for me have been as follows:

Thursday night between 6:00 and 8:00 CST. (3-day listing)

Sunday night between 8:00 and 9:00 CST. (3-day listing)

Here's why I've found these times to be best. If you start an auction on a Thursday night and it's a 3-day listing, it will end on Sunday night (eBay's busiest time). This is when there are the most users on the site and you'll be able to take advantage of the sniping bidders (bidders that bid at the very last second).
My second choice for listing an item falls on a Sunday night - again, a 3-day listing. The auction will close on Wednesday night and according to eBay, this the second busiest day of the week for bidders. If you can manage to have your listing end on the most high-traffic days, you'll have more exposure for the listing, and a higher chance of receiving a greater value for your product.

You also don't have to hang around your computer waiting to list an item at a specific time. There is automated software out there which you can download for free that schedules to start your listing for you based on the time and day you input.

I'd recommend using eBay.ca as opposed to eBay.com. The reason is, if you live in Canada, the selling fees are in Canadian funds, not American. Therefore, you have a better understanding of how much you're spending to list the item and how much you're going to bring in without running to a calculator to figure out an exchange rate. The same goes for different countries as eBay has a specific site for every one of you. eBay.com being for United States residents of course. If you can keep it simplified, do it.

Good luck!