1–3 months (roughly 3–8 weeks) before departure. For 2026, the average cheapest day to book a domestic flight is 43 days before takeoff.
While many believe in a "magic" day to book (like Tuesday at midnight), modern AI algorithms have largely debunked this. However, some patterns still hold: when should i buy flights
Standard windows shift during high-demand periods. For these, booking as soon as you see a "fair" price is recommended over waiting for a dip. 1–3 months (roughly 3–8 weeks) before departure
