It beat out X-Men: The Last Stand by a little over $40 million.
As of this, its second weekend, X-Men: Days of Future Past has grossed $500.2 million worldwide - $128.2 million globally this weekend alone - making it the top selling title in the 20th Century Fox and Marvel hero franchise, and the highest earning X-Men movie ever. It cost something in the region of $200 million to produce, so right about now some accountants out there are howling at the moon with joy. Or as close as accountants get to that kind of ecstasy, anyway.
International cash is the best kind; Days of Future Past owes its phenomenal income to its international audience, which put in $338.1 million of the total. X-Men: The Last Stand, the previous X-Men high earner, took in only $459.4 million, while X-Men: First Class took in $353.6 million in 2011.
Days of Future Past had been predicted to make something like $100 million in its opening weekend, and in fact made $90.8 million domestically in 3 days over the holiday weekend, topping $100 million on the fourth day.
This weekend Days of Future Past came in second, in terms of box office, to Maleficent, which took in $170 million on its opening weekend.
Source: Hollywood Reporter