What is the cheapest day to book a jetBlue flight? Planning ahead is crucial for securing the best deals on jetblue Airlines. Booking on Tuesdays or Wednesdays and during off-peak travel times can lead to significant cost savings. The cheapest days to fly on JetBlue Airlines are generally Tuesdays, Wednesdays, and Saturdays . These days typically have lower demand, which results in reduced Airfare prices compared to peak travel days like Fridays and Sundays