Q. What day(s) and time(s) of day will yield the cheapest tickets? And what days of the week are most advantageous to fly. We are flexible in our travel plans.

A. Airlines can adjust airfares at virtually any moment, and the number of seats at the lowest fares can fluctuate minute by minute, as the cheaper seats get sold, or the airlines make more seats available at the lowest fares.

So there’s no really best time of day or day of week to buy fares. That’s why it’s important to sign up for airfare alerts (to find services offering them, simply google “airfare alerts” and sign up.  Then pounce when the fare goes down, which really could be any time.

That said, if you’re flying on a route served by Atlanta-based Airtran or a competing airline on that route, then Monday nights and Tuesdays are a good time to look for fares, since Airtran typically has a sale every week. And if you’re looking for last minute weekend fares, Delta typically releases these fares late on a Sunday, and other airlines release them Monday or Tuesday.

The cheapest days to fly, as opposed to buy, are Tuesday and Wednesday, and also Saturday. The most expensive days are usually Friday and Sunday.