Uhm… No, it is spelled Judgement Day. With another "e" in the middle. And it is strange that I know that, considering that english isn't my mother tongue.^^

I went to google translator. It said it was spelled judgment. But now I checked my English dictionary and it said it was spelled judgement. Is there a chance that there is a difference between the way it is spelled in the UK and the way it is spelled in the USA?

Wikipedia, always here to help us (not the most trustable source you can get, but this is not an essay, so who cares):

"In a non-legal context, spelling differs between countries. The spelling judgement (with e added) is common in the United Kingdom in a non-legal context. In British English, the spelling judgment is correct when referring to a court's or judge's formal ruling, whereas the spelling judgement is used for other meanings. The spelling judgment is also found in the Authorized King James Version of the Bible.

In American English, judgment prevails in all contexts. In Canada and Australia, in a non-legal context both forms are equally acceptable, although judgment is more common in Canada and judgement in Australia. However, in a legal and theological context, judgment is the only correct form.[citation needed] In New Zealand the form judgement is the preferred spelling in dictionaries, newspapers and legislation, although the variant judgment can also be found in all three categories. Usage in South Africa is similar to that in Australia and New Zealand."
http://en.wikipedia.org/wiki/Judgment_(law)