Beyond avoiding flights on Mondays, Thursdays, Fridays, and Sundays, you should also cast a wary eye toward afternoon departures. This is the travel industry's version of rush hour. The skies are congested, delays are common, and fares are highest because it's when most people want to fly. To avoid high fares and delays, always look for the earliest possible departure.
We’re not advocating the controversial practice of hidden-city ticketing, in which you buy a ticket that connects in your end destination and do not take the continuing flight. This is against virtually every airline's rules of carriage. But you sometimes can save money simply by booking a flight with a connection rather than a direct or nonstop route. Connecting flights take longer (at least two additional hours), but if you're looking for absolute dollar savings, you may find it with this strategy. (Caveat: Connecting flights can occasionally increase
Here's a tip that may save you money on a complicated or long-term trip: Many airlines drastically increase fares for stays longer than 30 days, so if you're planning a long stay you may do better booking a one-way flight rather than a round-trip. It used to be true that one-way fares were not the equivalent of 50 percent of a round-trip fare, but that's no longer the case. Many major U.S. carriers (and some international airlines) today sell one-way fares for half of the cost of the lowest-priced round-trip airfare.
How Far in Advance YOU Should you Book your Flight?
How Far in Advance Should I Book My Flight?
Several sources publish data on the correlation between advance purchase period and airfares. The ideal time to buy a domestic ticket is 54 days in advance, says CheapAir, or seven weeks ahead, says Expedia, which are essentially the same findings.
For international trips, the ideal period is 171 days ahead of departure, according to the same Expedia report. CheapAir refines the estimates: 96 days before trips to Europe and 96 days prior to Latin America trips. Both sources indicate that you can come close to the absolute lowest price over a wide range of dates: CheapAir's "window" for good deals on domestic tickets is 27–114 days in advance; Expedia's window is 50–100 days.
Avoid booking too early and too late. Too late is especially bad; you pay a huge premium for buying within a week or two of departure—even on airlines that nominally assess no advance-purchase limit.