Why does Wolverine still have Adamantium claws in X-Men: Days of Future Past?

I haven't seen X-Men: Days of Future Past, so I can't comment on whether this was shown in the film, but this site does include quotes from the director, Bryan Singer, on the issue:

That wasn’t the only tempting breadcrumb that Singer threw to Empire, as part of the organization’s Days of Future Past marketing blitz. Fans who’ve been paying close attention to the footage and images released from the film thus far have observed that modern-day Wolverine appears to have regained his Adamantium-laced claws, despite the events that took place in last year’s The Wolverine; when asked by Empire, Singer hinted at a possible explanation:

Director Bryan Singer explains that Magneto’s ability to manipulate metal might have something to do with it. The Master Of Magnetism could, perhaps, “reconstitute the adamantium claws… [Wolverine] has a different relationship with Magneto, and perhaps Magneto could forge them.”

If you watch the movie The Wolverine until the end then you can see that Wolverine meets Prof. Xavier and Magneto at the airport and they ask to regroup. Both these characters help Wolverine to his metal claws back (with major help from Magneto of course, because he controls metal) so that they can fight the Giant Mutant Destroyers in X-Men: Days of Future past because Wolverine has the power to heal.

Helping Wolverine to get back metal claws is not shown anywhere but it's understood when Magneto says, "What do I want? I want your help" (in the airport scene) and in return Magneto helps Wolverine.

There are different types of Adamantium. The one that wolverine has is Adamantium-Beta. Wolverine possesses Regenerative Healing powers. During his exposure to Adamantium whilst having it bonded to his skeleton, his DNA was manipulated into seeing the Beta-Adamantium as his Skeleton. He can regenerate his Skeleton very quickly, but the Adamantium takes time to grow back. So he probably just had a few weeks with normal bone claws, until the Adamantium Beta grew back.

I hope this answers your question, if not please feel free to write a reply and i will get back to you as soon as possible.

Do you remember how in the x-men movies they hinted as to why his claws are adamantium? It's because they used bone saws to inject the adamantium into his bones which would mean that just like his bone claws regrew because of his regeneration they would actually be adamantium because his bones are adamantium. They have been making mistakes all over the series, and they are all easy to find if you watch what happens in chronological order, the only movies that have the same story line to it about the past is x-men # 1,2&3.