Hi @Mark6121
I tested the dates and they are bookable, so if you want a 3-month booking the guest can simply request the correct trip dates to see the price (you could offer more discount in the trip request if you want to give a better rate than the one already set).
Keep in mind that many hosts would advise new hosts to rather start off with quite a few short bookings, before deciding whether you want to do long stays.
(As an aside, there seems to be some extra text at the beginning of the listing description that should be removed)