How far in advance you should book your flight

Buying your flight at the right time can help you save some serious cash, but it's not always easy knowing when the right time is.

CheapAir.com studies over 1.5 billion fares every year to estimate how far in advance you should book for flights, from domestic fares in the United States to international trips around the globe.

Here are their results, along with insider tips from the George Hobica, founder of Airfarewatchdog.com, on how to score great flights:

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