Everyday I'm asked, "What's the best time to buy an airline ticket, and what's the best website to do it on?" I've got some new answers to share with you.

The Airline Reporting Corporation (ARC), which is like the back office of ticket selling for the nation's airlines, has monitored data continually over the last four years and found that the magic time to buy a ticket is generally six weeks before you travel.

Now, this is a general rule; it's not true for every ticket. But overall, if you're looking for a cheap fare, why not give it a try?

If you book way in advance or too close to travel, you're likely to overpay. Yet what the ARC findings don't take into account is that at the last minute, you really have a split scenario:  People can pay both the highest fares and the lowest fares. Based on demand, airlines may deeply discount their fares, particularly if the travel dates go over a weekend. Or they may slam you on price.

But for most situations, as a general rule, six weeks is the number to remember for both domestic and international travel. Based on my experience, I say that six-week mark can be kind of stretched out to between four and seven weeks.

Now, where do you get best deal? A Wall Street Journal test reveals there is no one definitive website that will save you money every time. Whoever is cheapest one time may not be cheapest the next time. So shop and shop and shop on multiple websites to save the most money.

And remember, the best deal flows to the opportunist. When you see a screaming deal, buy it and then figure why you want to go to the city you've booked!