Thanks Andrew - whewwww....this hosting experience is far different than the many years experience I've had as a treveler/guest with Airbnb. Yesterday evening I was able to successfully submit the change on my current guest reservation. I extended it another month as per my guest request.
Airbnb sent a message to him alerting him of the change and to accept within 24 hours. My message from Airbnb indicates they will tell me when he accepts.
Unfortunately, yes I did have to decline the 2 booking requests I had received in order to free-up/unblock my calendar days, to submit the change. I sent each declined booking person an apology and explained the reason.
My guest is really something...he just takes his own good time to reply to any message. I sent him a message (3 separate messages actually) yesterday explaining my challenges in trying to help him...and I was very nice of course.
Still, today with 12+ hours passed not a peep from him
I'll wait till I hear from Airbnb that he either has or has not accepted. If he has not accepted the change I submitted for him I'll proceed to manage my bookings for other new guests and let him know his original end date will be fine for us both.
I'll say too, this person is a superhost on the west coast. He has 50+ mostly positive reviews from guests. He has zero reviews as a guest. I'm his first host. I can see to that unless one of his guests leaves a bad review, he NEVER leaves a review for any guest.
So weird...time for another cup-o-joe right now I think