Landing the best TAP Portugal deals from AMS to TMS often comes down to booking at the right moment. You can save 17% on international flights when you book 18 to 29 days before takeoff instead of four to five months ahead. As an added bonus, you can pocket 17% on average by buying your tickets on a Sunday rather than a Friday, which is often the most expensive day to book.* It's a good idea to start searching for flights about one month before your travel dates.*Ideal booking window recommendation is based on average round-trip ticket prices for January through November for 2024. Best day of the week to book recommendation is based on average round-trip ticket prices for January through October 2024. All data sourced from ARC's global airline sales database.