I upload at 9:00-10:00 AM Pacific Time on weekends. It's what works best for me.

I did a survey and found- people are on around 17:00-19:00 (don't know if that's US or UK time though)

Unknown. But like @GINGER01 said. Just upload at your own time and prefrence. That time is my opinion but there is no true good upload time.

There isn't really a good time to upload. So many people around the world that play this game and many different times when people upload. Just upload when ever you want to. Some people are on the web site when other people half way around the world are asleep. Don't wake up in the middle of the night or during school just because other people say what time is the best. If your creation gets noticed then people will see it.

@KDS
5:00pm? That's about 12:00pm where I am, what time zone is that anyways?

On a weekend around 5:00 PM on the clock on the bottom of the site.