The Best Day of the Week to Book Airline Flights

The Perfect Time

Peter Greenberg, author of "The Travel Detective Bible" and editor of the Peter Greenberg Worldwide travel website, recommends that those looking to buy the cheapest plane tickets do so at 1 a.m. Eastern time on Wednesdays. This is when airlines typically change over their pricing for the next week, meaning that the older, cheaper fares are available for only 24 more hours before they are canceled.

How It Happens

Greenberg explains that airfare cycles start on Friday and can go two ways. First, a larger airline can raise its rates late that evening. By Saturday morning, most of the major airlines have followed. But if competitors don't match the fare, the airline that started the increase is likely to drop its rates back to close to the original level by Sunday night or Monday morning.

It also works the opposite way. In most cases, a smaller airline will start an airfare war by dropping its fares, also late Friday. During the weekend, most of the larger airlines will seek to match the fare so they can keep up.

Avoid the Weekends

Greenberg recommends that you not purchase airline tickets on weekends because the increase--or decrease--in rates can work against you. Buy a ticket on a weekend in which an airline has raised its fare, and you could end up spending too much and learn your mistake too late. Buy a ticket on a weekend in which airlines are cutting fares, and you still might not get the best deal. That's because depending on how the lower fare is selling, another airline could jump in on Monday or Tuesday with an even better deal.

Know Your Time Zones

Most of these airfare computers are set to the airline's national headquarters, Greenberg says. It helps to know where the airline is located, so you can purchase at a time that's appropriate for your time zone. For instance, someone who lives on the West Coast and is purchasing a ticket from an airline based on the East Coast should purchase at 10 p.m. Pacific time on Tuesdays.