But there’s always more to savvy airfare booking than meets the eye.

By Nikki Ekstein
February 25, 2016
Credit: (c) Per Breiehagen

According to CheapAir.com, it doesn’t matter if you book your airfare on a Tuesday, or a Saturday, or really, any other day. What does matter is how far ahead you book. The online booking agency reviewed a whopping 1.3 billion airfares that were searched and booked on their site to pinpoint exactly when the best values were secured, and now, the consensus is in: when it comes to domestic fares, 54 days is the magic number.

But it’s never black and white when it comes to booking fares. (Though you can click here to see our most recent attempt to break down the clearest terms for different types of trips.) For the purposes of their study, the data analysts at CheapAir reviewed how prices fluctuated for 3 million different trips over the course of nearly a year. They tracked prices for 320 days leading up until the given departure date, and watched as a trend line emerged. What it revealed: there’s a sweet spot for domestic fares that CheapAir calls the “Prime Booking Window,” and it spans from 21 to 112 days ahead of your departure date. Booking in that three-month span will offer maximum odds for a bargain booking. Book between three and a half and six and a half months out, and you’ll pay a small premium—but perhaps buy yourself some peace of mind, says the study.

Of course, it doesn’t take data scientists to know that booking more than six months out—or less than three weeks out—will bump up prices. The real nuance in airfare pricing depends on your points of departure and arrival, and several other services have dedicated themselves to predicting the best time to book according to your specific route. And the smartest travelers will protect themselves from falling prices by employing services like Yapta, which can rebook your ticket if the price drops—and pay you the difference. (CheapAir itself has a price drop guarantee that’s good for up to $100.)