So, Spirit Airlines Low Fare Calendar would be your go-to tool for finding the cheap fares throughout the month. It indicates the least available dates for your route so that you could plan a flexible, low-cost journey. If you just need a quick getaway or would rather plan ahead, the Low Fare Calendar makes it easy-and-comparative for you to plan ahead in choosing an itinerary that can get you the best prices as it compares prices for that date.