Lower Airfare Near the Witching Hour?

Totally in the experimental stage still...but for the past two-three weeks when searching for airfares, they were almost always cheaper when I looked late at night (between 9pm and 12am EST) than when I searched during the daytime at the same flights.

By waiting until nighttime to buy, the price drop was significant going from as high as $346 to as low as $211 for a one way ticket, which is obviously an even larger gap if you need two of them.  Since a lot of airlines are changing over to an equal-equal pricing system, where you even buy your round trip tickets by combining individual one-ways, it's worth thinking about this daytime vs. late night buying timetable.  So if you're searching, try it for yourselves, and let me know if you guys are getting the same results!