Sunday is generally not the best day to travel if your goal is to save money or avoid crowds. In 2026, Sunday remains the most expensive day of the week for both domestic and international flights, as it is the primary return day for weekend travelers and the start of the week for business commuters. Flying on a Sunday can cost 10% to 15% more than mid-week flights. For the best deals, Tuesday and Wednesday are the "golden days" for travel, offering significantly lower fares and quieter airports. However, Sunday can be "best" in a non-financial sense: it allows you to maximize your weekend and return home in time for work on Monday. If you must fly on Sunday, booking your ticket on a Saturday or late Friday may sometimes reveal small price drops, though the flights themselves will likely remain packed compared to the Tuesday lull.