Travelers everywhere would like a magic potion to predict the best time to buy an airline ticket to get a good deal at the lowest price.
Although seasoned travel advisers say there is no perfect moment to book an airfare, a recent study by Expedia Inc. and Airlines Reporting Corp. (ARC) suggest that based on thousands of flights in 2016, the lowest average ticket prices were purchased on weekends, especially on Sundays.
Expedia crunched numbers gathered by ARC from corporate travel companies and online and brick-and-mortar travel agencies and determined that flights within the United States booked on Sunday were 11 percent cheaper. Flights from the United States to Europe were 16 percent cheaper, and between the U.S. and Asia, fares purchased on Sunday cost 10 percent less.
"Business travelers booking at the last minute, those fares will typically be higher," Thackston said. "Airlines are aware that leisure travelers are looking on the weekends, so they'll make those fares available on the weekend."
Others say the picture is more complicated. Prices constantly fluctuate, based on how full the plane is, the route - and competition on the route - the date of travel, and day of the week.
"I have never experienced that purchasing the ticket on a certain day of the week makes any difference," said Jeffrey Erlbaum, president of ETA Travel in Conshohocken. "The fares don't change very much from day to day. It's availability that generally makes a difference. Somebody might have booked that flight, a group, and that's going to jump your fare up.
"I've seen no rhyme or reason to the fare sales," Erlbaum said. "A fare between two points can go on sale any time, but if availability on the flight you want isn't there - if the flight is full - that's going to make a difference."
George Hobica, founder of the fare alert website Airfarewatchdog.com, said: "As far as Sunday being the best day to buy tickets, that's nonsense. An incredibly low fare can be snuck into the reservation systems any day of the week in terms of booking."
But not in terms of flying, he said. "Tuesday and Wednesday are the best days to fly."
Erlbaum said availability on flights is greater on Wednesdays, and that translates to lower fares. "As the flight gets fuller, those lower-fare buckets get sold out, and you are pushed into a higher-fare bucket."
Tickets purchased 21 days in advance are usually cheaper than closer-in purchases. The Expedia report found that average round trips purchased three weeks before departure were as much as 30 percent lower, especially for trips within the United States and Europe.
In many parts of the world, itineraries that include a Saturday night stay-over are less expensive - up to 57 percent less, the report said.
The study noted that, overall, average airline ticket prices in 2016 continued a three-year decline - the lowest since 2013 - due to increased airline seat capacity, an improving economy, and lower jet fuel costs.
In Philadelphia, average round-trip ticket prices dropped 13 percent to the 13 most popular destinations in 2016 when compared with 2014, according to ARC. At the same time, the volume of passengers at PHL was up 7 percent in 2016 versus 2014.
Erlbaum, the Conshohocken travel agent, agrees that airfares are generally lower, but not out of every city, on every route. "Competition plays a major role. The legacy carriers - American, Delta, United - do not compete as much on fares as if Southwest or JetBlue is flying."
Hobica said, "On some routes, fares have gone down more than the average, and some routes between smaller cities where there's less competition, they've gone up more than average. But, in general, especially when you adjust for inflation, the trend has been down.
"People don't perceive it that way, but it's like many things: Perception is not always in line with reality. The reality is that with airline consolidation, on average, airfares have been going down," Hobica said.
"We saw fares from Philadelphia to London recently for $500 round trip, including taxes, for next summer."