Air-line often release new fares and sales on Monday evenings, making Tuesday a prime day for finding discounted tickets. The cheapest day to buy 𝒟𝑒𝓁𝓉𝒶 Airline tickets is typically on Tuesdays, Wednesdays, and Saturdays (OTA . How many days before a Delta flight can you cancel?The cheapest days to fly on Delta 𝔸𝕚𝕣lines are typically Tuesdays, Wednesdays, and Saturdays These days tend to have lower demand which allows the 𝔸𝕚𝕣line to offer more affordable fares.