Q: When is the best time of the week to find the lowest airfares? I've heard it's on a Tuesday or Wednesday.

A: While it's true that more seats are available at the lowest fares if you travel on a Tuesday or Wednesday (and sometimes on Saturdays), that doesn't necessarily mean you'll save money if you purchase your fare on those days. Airlines can lower their fares at any given moment, seemingly on a whim. In fact, domestic airfares can change up to three times daily, and once a day on weekends, so it's a good idea to check in the morning, around noon time, and after about 4 in the afternoon. Also, I've found that some of the most amazing unadvertised sales appear on Saturday mornings. Why? One theory is that because when one airline unleashes a "sneak" sale, since airfares are updated only once on Saturdays other airlines can't respond immediately.