TLDR: For internal flights - 3 weeks to 3.5 months before flight For international flights - 2 months before flight Interestingly, it's often cheaper to order

TLDR: For internal flights - 3 weeks to 3.5 months before flight For international flights - 2 months before flight Interestingly, it's often cheaper to order a ticket 2 months in advance than 10 months in advance.