Google Flights identifies optimal booking windows for domestic, international and holiday

Google Flights analysis shows that the lowest price for domestic flights typically occurs 39 days before departure, with a range of 22 to 57 days, while international flights reach their lowest price 89 days before departure, ranging from 50 to 133 days.

For specific holidays, the study finds Thanksgiving fares are lowest 34 days before travel (21 to 57 days range), Christmas fares 56 days before travel (33 to 67 days range), spring‑break fares 50 days before travel (29 to 64 days range), and summer vacation fares can be booked as late as 21 days before departure (20 to 47 days range).