@Sladan1 It is allowed and certainly possible to book 8 months ahead on Airbnb. But I'd recommend taking the following steps to avoid a major mishap:
1. Choose a host with a consistent record of good reviews and zero cancellations, so you can be confident of their commitment to the booking.
2. Pay careful attention to the host's cancellation policy, and the time frame within which you're eligible for a partial refund if your plans change.
3. Purchase travel insurance that covers trip cancellation if you're concerned about how much you might stand to lose if circumstances beyond your control intervene.