why not what date is today?
"What date is it today?" is correct English and might work. "Today" is a time adverb, not generally a noun. Report it though and see if they add it. There are a lot of alternative answers missing.
Today is the day I change your perspective on this. While it might not be considered grammatical, it is certainly idiomatic to treat it as a noun in many cases.
'What date is it today' is not accepted either...
"Report it... and see if they add it."
I did, and they didn't.
"What date is today?" is a correct translation. It is also correct English and should be accepted
"What is today's date?" How is that?