A new study has found the best time to buy plane tickets is exactly 70 days before your flight.
CheapAir.com's research, released this week, examined more than 917 million airfares with destinations in North America.
It found the worst time to buy tickets is six days before takeoff or less, but booking too far in advance can also cost you more.
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The study divided ticket buying periods into six 'zones', with the prime booking window being 21 - 121 days ahead of the flight.
The other periods are the Hail Mary zone (zero - six days from takeoff), the Playing with Fire zone (seven - 13 days out), the Push Your Luck zone (14 - 20 days out), the Peace of Mind zone (122 to 168 days out) and the First Dibs zone (169 to 319 days out).
The study also found Wednesday is the cheapest day to fly while Sunday is the most expensive, but what day of the week tickets are bought makes no difference.