A question about the study question 「この課題の期限がいつか知っている？」

Japanese
#1

I feel like I’m overlooking something very simple here, but is there a reason why it’s いつか rather than いつ to ask when the deadline is? If いつか usually means someday/sometime?

#2

Question-phrase + か (JLPT N4) | Bunpro

It’s a question within a question.
The sentence structure is basically “When’s the deadline for this topic/assignment? <— do you know the answer to this question”