He had inquired from you, not booked. He didn't follow through.
"Not possible" means that either the 24 hour window has passed and pre authorization or tentative booking has expired, and/or he booked somewhere else.
I had it a few times that people inquired about the dates, though they were clearly open on the calendar, then they never booked, similar to inquiring about check in times - yours seems to be wide open from 3 pm to midnight...and then not following through.
No clue what the point of it all is....