I’ve noticed movies and videos are released on Tuesdays. It seems to be a pretty arbitrary days and doesn’t have any apparant advantage over other days.
IMO, later in the work week might be better since thats when one begins to think about relaxing in the weekened with a new release.
Short of a vast conspiracy involving truckers, I don’t see the reasoning. 
Tuesday is traditionally a slow day, retailwise. Do it too close to or on the weekend (Thurs, Fri, Sat, Sun) and you’re basically making a good day better; retailers would like to have seven good days rather than four good ones and three poor ones.
I’m not sure why they don’t do it on Wednesday, which is also pretty slow, but it’s probably all due to tradition at this point.
Asked here before. The answer is about 2/3 of the way down that thread.
In Australia it’s thursday, though I seem to recall that LOTR is coming out on the 26th, which is a Friday. Of course, it would be a bit silly to have it opening on Christmas…