Well this is some interesting research. Out of my off-hand and roughly scientific research, my statement of "almost all" was quite off. I found that all of the

Well this is some interesting research. Out of my off-hand and roughly scientific research, my statement of "almost all" was quite off. I found that all of the major carrier websites I could remember off the top of my head did not employ the date-ahead practice. Delta - no US Airways - no Southwest - no Virgin America - no Continental - no I followed that by a Google search for "flight search" and checked the sites that came up in roughly the 1st and 2nd pages. Where I put "yes" and the date range, this date range was pre-populated. Based on Google for "flight search" Priceline - no Travelocity - no Kayak - yes 9/27/11-10/4/11 Expedia - no Cheapflights - no Flightsearch.com - yes 9/27/11-10/4/11 Tripadvisor - yes 9/27/11-10/4/11 Farebuzz.com - yes 9/27/11-10/4/11 http://www.skyscanner.com/ http://www.skyscanner.com/ - yes 9/27/11-10/4/11 Finally, I checked YC's own Hipmunk, and they do not do it either. Hipmunk - no So my original statement was at least partly false. It doesn't seem like "almost all" after all. And the ones that I could find doing the date-ahead practice all had identical dates. I suspect all of them use the same backend search product. I don't care enough at this point anymore to follow up on this anymore, so I'll leave it at that.