Translation:What date is it?
There's nothing to suggest the question is about today. Literal translation would be, 'what month what day?'
It's a common way to ask for a date because it's obvious in context what date you're asking about, like so:
我们想去涮火锅，你来吗？ We're thinking of going for hot pot, you coming? 几月几号？ What date?
I think Duolingo helps you more in translation than in actually learning.
I mean, for learning purposes you could say "what month, what day (is it)?" as long as you understand the meaning of it.
Know how you would say the same thing in English - that's translation, which may be irrelevant for those who just want to be able to communicate.
Now keep learning, I just wanted to say that, and remember that's merely a thought, not a fact :v