It might be that movies are scheduled to be released on days where there is no other mayor movie released in the same time frame in order to not cannibalize each other entrances. Another thing to consider is that maybe big feature films such Iron Man 2 might be released earlier on countries where there is a high tendency of piracy. In this manner they are able to gain the profits that otherwise could be lost if the piracy industry has the time lag to make the copies and flood this markets with movies that are released months earlier in the USA.
Back to the Movies - 2009 was released on: USA: 30 January 2009
Pruning the Movies - 1915 was released on: USA: 1 January 1915
Richard Roeper and the Movies - 2009 was released on: USA: 2009
Movies and Music - 2010 was released on: USA: 5 July 2010
Movies for Guys Who Like Movies - 1999 - 3.41 was released on: USA: 8 October 2001
Swingtime in the Movies - 1938 was released on: USA: 1938
The Movies - 1925 was released on: USA: 4 October 1925
At the Movies - 1982 was released on: USA: 26 September 1982
Cheap Movies - 2014 was released on: USA: 2014
What I Learned About--- From the Movies - 2007 was released on: USA: July 2007
Regions are global areas defined by the BluRay consortium. In order the allow the introduction of movies in different countries on different dates, most Bluray movies have a region code embedded in them. Bluray players will only play movies authored for the region in which they are sold. There are movies on the market, however, that are region-free, and can be played on any Bluray player anywhere in the world.
Pruning the Movies - 1915 was released on: USA: 1 January 1915
Richard Roeper and the Movies - 2009 was released on: USA: 2009
Movies and Music - 2010 was released on: USA: 5 July 2010
Jerry in the Movies - 1916 was released on: USA: 7 January 1916
Movies 101 - 2009 SUSPENDED was released on: USA: 2009
Bill Kennedy at the Movies - 1956 was released on: USA: 1956