Travelocity released their Fourth of July Booking Barometer results, proving what everyone already knows: booking flights early saves money. What you might not know is exactly how much it can save you.

The Barometer analyzed five years of data, from 2007-2011, and found that ticket prices go up as the holiday gets closer. Contrary to what some believe, airlines do not get desperate to fill planes. Booking three weeks out instead of the week before could save you 20% on air fare. Case in point: Flyers who booked their tickets three weeks before the Independence Day holiday paid $342 on a domestic flight. Those who booked their flights a week before the holiday paid $412.

If you're thinking that traveling after the holiday has passed will save you money, think again. The most economical approach is to depart before the holiday weekend. As an article on TravelIndustryWire.com explains, "For the best deals travelers should depart before the holiday and return mid-week. This could save travelers as much as $235."

Travelocity's blog (https://www.windowseatblog.com/2012/06/travelocitys-guide-fourth-july-travel-savings) states, "The averge domestic airfare is up six percent over last year." A stay-cation or a closer destination may prove to be a more frugal decision, even with the price of gas factored in. If you must fly, however, then the message bares repeating: Book early -- almost a month in advance -- to save money.

Not sure where to go? This article offers some suggestions for popular destinations, as well as some activities in each area.