This is from an English teaching web site School conversation (see:01:15)
Who can tell me what day is it today?
As we know, a question sentence changes structure when it functions as a subordinate clause. E.g "Tell me where you are going?" (not where are you going?")
So, I would expect the same change of structure in the quetion Who can tell me what day is it today? However, it does not change and the subordinate part seems to have remained as is.
So I want to ask; should it not be put this way: "Who can tell me what day IT IS today?