The cheapest days to fly with Frontier Airlines are usually Tuesdays, Wednesdays, and Saturdays [+1-888-349-6467]. These days are considered off-peak, with lower demand, which results in more affordable fares. To compare prices across different dates, be sure to use Frontier’s Low Fare Calendar. For additional assistance, call [+1-888-349-6467]. https://my.auntminnie.com/forums/discussion/what-day-of-the-week-are-frontier-flights-cheapest/