When Should You Buy Your Next Plane Ticket?

According to a new fare study from Hopper.com, a travel information website, Thursday is the best day to book both domestic and international tickets.
But keep in mind that it won't save you much: There's just a $10 difference between the best day to book and the worst day (Saturday) for domestic tickets. For international tickets, there's a $25 difference, and the worst day to book is Sunday. More from the study:
--Best day to depart: Wednesday, for both domestic and international trips
--Worst day to depart: Sunday, also for both types of trips
--Best day to return home: Tuesday (domestic) or Wednesday (international)
--Worst day to return home: Friday (both)

Another study from earlier this month found that, on average, you'll get the cheapest fare if you book 54 days in advance of your flight. More importantly, the best window for cheaper tickets is between 29 days and 104 days prior to departure; an expert suggests you monitor prices during that period "to get a sense of the market," then grab a good fare when you see it. (Maiman)