Would it not be "Hvad hedder du?"
It is like how you can say, "What is your name?" and "What are you called?" in English.
Thanks for clearing that up mate :)
I wondered the same, I couldn't help but be reminded of 'Hva heter du?' in Norsk. Thanks for asking this!
"Hvad er jeres navn?" should also be correct since it's just a formal way of asking about someone's name.
Why not "sit navn"?
It could be Hvad er dit navn? Sit would refer to 3rd person: 'her' or his'
Since there is no subject being provided it can be referring to anything. Sit is used when the subject is already defined
The person being asked is 'du'.
what does hedder means
It's a verb for having a name. There isn't a equivalent in English, so it is translated to "be called" or "be named".