Do the seats get booked on flights up to the last minute, or is it the same in the real world, where an hour before check in closed? My first flight is due to take off at 1700hrs and was wondering. Also how are bookings actually made, do I have to be logged into the game, or is it time controlled etc. Just interested how it works.

Each airport has a "demand calculation" time. You can find this time in the information page on that particular airport. When that time comes up, every day, passengers book from that airport to different destinations all over the country/world. Bookings only happen at this time, and only from that particular airport.

And you can have a flight leaving next minute after booking calculation demand. But you run a risk of time lag in computer processing... so you better schedule it couple of minutes after demand calculation for your particular airport, e.g. 5 minutes after demand calculation is OK.

If you have demand calculation at 17.34 HT, schedule the flight to leave at 17.39 HT. But after one or two cycles, the demand calculation really does not matter (because after the first cycle, 17.32 HT departure would be actually assigned booking within the first cycle next day). I hope it makes sense.

Another thing, A -> B -> A will have two different demand calculations, one for A -> B at A time calculation, and one for B -> A at B time calculation.

If you have a local ground network (G) that connects to A, you will be also calculated G (via ground) A -> B demand at the time G demand calculation happens, and you will also be calculated B -> G (via ground) A at the time B demand calculation happens.

Also one important thing, departure/arrival times have no meaning here besides being just a time reference. AS pax are as willing to take 2.07 am flight departure for the same price as 9.40 am or 4.06 pm. So there is no "penalty" for off-peak/redeye flights.