Rather than start a new thread about the same issue, I will enter my issue into here.
I am playing in Private World #798 (Airline ID: 29329) with a hub at HND. I have 50 flights scheduled (which the game properly recognizes), but it is requiring 51 slots to operate them. My Tokyo-Izumo flight, which I have set at a frequency of 1, seems to be requiring 2 slots on each end - my single gate at Izumo shows that it is 20% utilized despite the single flight. It doesn't hurt me at the Izumo end, but it is currently forcing me to rent an entire additional gate at HND since I need 6 gates for 51 slots as opposed to 5 gates for the 50 slots I should need.
Thanks.