Date confusion and Lexicon's timeline again

Well, here we go again. Currently, we are using 24 May as the date for when the champions are informed of the third task of the Triwizard Tournament. And if we accept this as the case, then we have to accept for our own internal consistency that the events of the next day occur on 25 May and Harry's receipt of Sirius Black's letter on 26 May. Now, the date makes sense because in the book, it is clearly stated the champions will be informed precisely one month beforehand what is to come. The Lexicon, however, gives 27 May as the date of when the champions are informed, and goes from there. I was scratching my head, trying to figure this out, and finally realised what they're getting at here-- they're basing this off the fact that Transfiguration lessons were previously stated to occur on Thursdays, and the text states that McGonagall held Harry back in a Transfiguration to inform him that the champions were to gather that evening to learn about the third task. Thoughts? ProfessorTofty (talk) 06:18, May 20, 2013 (UTC)

That's because they don't count "a month" or "month-old" as one month the same way we do: they count it as "approximately a month" and then use real dates to try and make it fit. For example, on 24 July, Harry receives The Smallest Bedroom and sees Dudleys "month-old" cine-camera. The Lexicon then says that Dudley's birthday was a Saturday in the year of the first book, and they move it back to fit in with the real year. So really, without that Dudley's birthday is 24 June. Or so, I believe. --Hunnie Bunn (talk) 11:47, May 20, 2013 (UTC)
And normally I can understand the point of that kind of fudging. The problem here, as I noted, is that the text states to us that the champions were informed precisely one month beforehand. Which means that unless they were being very careless with language, it should have been exactly a month before they had the third task, and not any earlier or later. ProfessorTofty (talk) 18:10, May 20, 2013 (UTC)
Exactly. --Hunnie Bunn (talk) 18:13, May 20, 2013 (UTC)