Hi @Julie4652 🌸 Did they maybe send you a message using the “contact host” link (it is called “an inquiry” in Airbnb language not a request) - they just sent you a message basically. “A request” is when guests have already decided to stay and added credit card details and only need you to accept. A request will block your calendar until you have accepted or declined).
In your case they must have send you “an inquiry” since it isn’t possible to send “a request” with a day in between that isn’t included in the booking - as already mentioned by Emiel. Your calendar is set up to only accept at least 3 days-in a row-bookings.
If I were you I would write the guest and say that unfortunately it isn’t possible to have a hole in-between booked days as it isn’t possible to rebook the unused day to someone else.
They will have to book for 4 days.
I have hosted a lot and I would see it as a huge red flag that they expect to occupy a place for 4 days but only want to pay for 3. I think it is rude, entitled and disrespectful. I would probably decline.