Board Thread:General Discussion/@comment-5124674-20150518181705/@comment-1298029-20150519170326

I think the proper heuristic approach is: When you detect a conflict in the timeline, research all available material for more information. If known information leads to a logical conflict in dates (such as described above with the Friday), that conflict is certain, and no other information is available, use the newer information, as that's simply writer error in maintaining continuity. There can even be a note on the page that this is so.

If more information can be found but does not resolve the conflict, the information that turns up most often should be taken (e.g. if 5 movies logically imply a date, and a 6th implies a different one, then the one that's mentioned 5 times should stay even if the 6th one is the newest). This reflects the fact that such a situation would likely occur only when the writers were trying to keep the more frequently mentioned date as canon (why else would you get a match in several differnt works), but someone on the newer work simply slipped up and wrote in a different date.