Synonyms for Judgment Day (same or very similar meaning)
WordNet sense 1 ((New Testament) day of the Last Judgment when God will decree the fates of all men according to the good and evil of their earthly lives):
doomsday, crack of doom, Day of Judgement, Day of Judgment, day of reckoning, end of the world, Judgement Day, Last Day, Last Judgement, Last JudgmentFrom the ODE community, based on WordNetadd/edit