Forgive my ignorance, but what is unique about March 25? Why is there a significance to the movie release being near that date?
March 25 is the feast of the Annunciation ... nine months before Christmas.
You don't have Christmas without the conception.
There is a recent story in Russia of a young man who would stop at anything to help form a Catholic Church there (after the fall of Communism). His mother was going to abort him, but she realized she was scheduled to do this on March 25th, which she had always been taught was a very holy day.
It is referred to as the day that the Angel Gabriel 'Announced' that Mary would be the mother of Jesus - the Orthodox religions call her the Mother of God.
The Greek Orthodox, Russian Orthodox, Ukrainian Orthodox, Ukrainian Catholic, Roman Catholic, etc., all celebrate this. It is generally referred to as the 'Annunciation' or 'Feast of the Annunciation'.