yes, but we usually use dni. "Dnie" use poets when they need rhyme, and they are in some fixed expressions.
let the weekend have any number of days, 'weekend' is a singular unit! Just like we use has and have with 'It': in a question - Does it (a weekend) have...? and in a statement- It (a weekend) has..... Marek is right.
Yes. Or even "Weekend is two or three days?", with the declarative word order.
That's what I wrote (A weekend - is this two or three days?). Was not accepted.
Well, you split the question into two parts, so that's pretty different... "Weekend - czy to dwa, czy trzy dni?"
For those of you stating that a weekend is singular: yes, it is. However, "does" is driving the verb here. As an auxiliary verb, "do" is always followed by the base form of the main verb infinitive, i.e. "[to] have". E.G.
Does the weekend have two or three days? The weekend has two days. Does he have time? Yes, he has time.