The study also broke down which airlines had the cheapest fares on certain days.
Delta Air Lines had the cheapest prices on Thursdays, with an average savings of $35.
For passengers booking on low-cost carriers JetBlue and Spirit, Mondays and Tuesdays were the cheapest dates to book.
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The report analyzed over 44,000 different flights over the course of four weeks to determine the price fluctuations.
JetBlue has aBest Fare Finderto find an airfare deal.