When should you book your trip?

Everyone seems to have advice on the subject of the best time to book a trip, but what is the real truth? For every person that tells you to wait until the last minute for the best deal, another person will tell you that you should book as far in advance as possible. A new study was recently completed by the Airlines Reporting Corporation that compared hundreds of travel sites, airlines and agencies to finally reveal the best window to book your trip.

For domestic flights within the U.S., it turns out the most ideal time to book is roughly 6 weeks from the date of travel. The study gathered data from the past 4 years and found the average lowest price was in the "sweet spot" of 6 weeks. So, is the 6-week rule in play for international flights as well? The answer is no, as the study found that the ideal booking time was much farther in advance, in the range of 24 weeks from the date of travel. Although it's long been a tactic to try and wait for a last-minute sale for international flights, experts say that is becoming a risky approach with less chances of success than in previous times. A trip to Europe in the summer should be booked as early as possible, with fare increases common throughout the Spring. The ideal window is 21-22 weeks out for flights to major European cities.

If you're looking into traveling to the Caribbean to escape the cold U.S. winter (perhaps for a kosher cruise), plan on booking 11 to 12 weeks in advance. The most popular destinations, such as Costa Rica and the Bahamas, are exempt from airfare wars generally. Unfortunately, the fares are high year-round and deals are very difficult to come by.

Several tools are available to assist you in your airfare research. Bing.com offers a Price Predictor that uses algorithms to determine how likely a fare is to rise or fall during the next seven days. It applies to flights from more than 250 cities in the United States and to top domestic destinations and major hubs in Europe.

For the cheapest dates to fly, go to Itasoftware.com, which allows you to scan an entire month’s worth of fares. To buy, you must go to the airline’s Web site or online agencies like Travelocity.