No easy formula for best time to book airline tickets

Written by David Koenig, AP Airlines Writer
Travelers dream of the perfect trick to find the cheapest airfare every time, every trip.
There are theories, some of them backed up by real number-crunching — shop on a Tuesday, 57 days before your flight. But using a tidy formula to find the cheapest fare may be as futile as trying to time the stock market.