Used aircrafts can be sceduled when they are leased - 14 days before delivery.
How long before delivery can a new aircraft be sceduled? Is it true that it not can be sceduled before it is delivered?
https://www.airwaysim.com/game/Manual/Aircraft/New/#Delivery
"Your aircraft will be available for route scheduling 3 weeks prior to the actual delivery date. You can see the 'pre-delivery' state aircraft with yellow color coding on both Scheduling and Aircraft on order pages."
Thanks :)