How far in advance should I book a visa for Thailand for a family trip next December?

When planning a trip to Thailand for 1-2 months in December next year, it is advisable to book your tourist visa approximately 2 months in advance of your departure. A tourist visa is typically valid for 90 days from the date it is issued, and you can apply up to 90 days before your planned entry. Additionally, most nationalities can enter Thailand without a visa for 30 days and can extend their stay by an additional 30 days if needed.