I've taken a course on ebay, and the best time to sell MOST items (not all) is Sunday evening between 10 PM and 12 midnight. The reason is, most people aren't on the computer Saturday nights or Tuesday afternoons, etc. That said, me as a photographer, I know Sunday nights is NOT the best time to sell equipment. Photographers are thinking equipment when they're in their studios, but not the first thing in the morning at 10 AM. Their slow time might be 3 PM. So there's no best time for sure. The name of the game is to get as many potential buyer's looking at your ad.

Good luck!

1991 300d, 90k