The world was ending and that. Sucked. However, that didn't mean they couldn't do something before then. In a way, knowing all they had left was a month was liberating, when she refused to allow herself to think about things long enough to get depressed about it.
One thing was ninja being allowed to travel freely. There was no point in keeping their ninja at home when no one would live longer than a month anyway.
If nothing else, at least they could go and see all the sights and sounds the world had to offer before they were gone.