Holiday flight deals? Think ahead. Waaaay ahead

If you're thinking about great deals for a holiday flight somewhere, do your shopping next week.

Not for the upcoming Memorial Day weekend at the end of May -- but for a Fourth of July trip.

That's according to Hipmunk -- www.hipmonk.com -- a flight/hotel discounter. Its "2014 Summer Travel Survey" forecasts that travel for Independence Day will be heating up quickly, and that historical data indicates the best time to book such a trip is the week of May 26-June 1.

On average, the report says, those last year who booked the week of Memorial Day spent $417 in airfare... but those who booked three weeks later spent -- on average -- 31 percent more: $547.

With consumer money tight and airlines keeping a close watch on profits by upping their "load factor" -- filling as many seats as possible, even if it means reducing the number of flights --  there's little surprise that the search for holiday discounts is a hot topic.

Alison DaRosa, a veteran travel writer based in San Diego, wrote an article in early May for the online edition of the San Diego Union-Tribune  about timing your airline buys.

Drawing on a report released this spring by another discounter -- CheapAir.com -- she notes that "most flights open up for sale about 330 days in advance" and that "ticket prices for those individual trips will change an average of 92 times before takeoff."

You can find the CheapAir report at http://bit.ly/MAT3D.

The best time to buy?

"The simple answer," CheapAir reports, "is that in 2013 the best time to buy a domestic airline ticket was 54 days in advance, or 7 1/2 weeks on average."

It also states, "The worst time to book your trip was the last minute. No big shocker there. The day before was the single worst day, two days before was the second worst, etc. etc. all the way up to 13 days in advance."

Also bad? Booking too far in advance.

And the timetable for anything involving holidays seems to defy logic.

DaRosa's article notes that CheapAir found the best day to book domestic tickets for both Thanksgiving and Christmas this year will be ... June 4.

June 4, by the way is celebrated as  Independence Day in the Pacific island nation of Tonga.

If you were planning on attending those festivities, I really can't tell you if there would've been a "best day" to book that flight. For a trip that expensive, there might not be one.