I've noticed a "quirk" with a couple of recent timetable searches I have performed - flights are returned whose dates of applicability are outside the date range I have specified.
An example:
Searching for the timetable for DOH-NBO on
25/01/2016 with the "Search up to 7 days from this date" ticked
The results returned are (scroll right to see highlighted dates that are outside my specified date range):
Results from ExpertFlyer.com
Code:
Flight Timetables Search:
Search DOH to NBO on 25/01/16 up to 7 days
Flight Stops Depart Arrive Aircraft Duration Frequency Effective Ending
QR 1337 0 DOH 3:55 NBO 9:10 320 5 hrs 15 mins Daily 25/10/15 16/07/16
QR 1337 0 DOH 3:55 NBO 9:30 320 5 hrs 35 mins Daily 03/07/15 24/10/15
QR 1339 0 DOH 7:35 NBO 12:35 320 5 hrs 0 mins Daily 26/10/15 26/03/16
QR 1339 0 DOH 7:35 NBO 12:50 320 5 hrs 15 mins Daily 01/09/15 23/10/15
QR 1339 0 DOH 7:35 NBO 13:10 320 5 hrs 35 mins Daily 03/07/15 31/08/15
Not too difficult to cope with in the example, but for another search I did (SYD-LAX on the same date) the returned results are daunting, even when filtered to just show the QF flights (16 of the 18 rows are outside the specified date range!).
Note that unticking the "Search up to 7 days from this date" returns results that are in range.