The timeline on the DVD *confirms* canon;

[Ali]

No: HPFGUIDX 56020

--- In HPforGrownups at yahoogroups.com, "psychic_serpent" 
<psychic_serpent at y...> wrote:
 
<<< other people who've posted here in the past have argued that 
there are in fact exceptions, because THEY are the exceptions.  So, 
the fact that we've had folks speaking from personal experience, 
living, breathing examples of people who didn't have to wait a year 
to start school in the UK means that it DOES happen. <snip>
 For pete's sake, this is HERMIONE we're talking about!  
This girl is scarily smart.  I don't think it's just because she's 
nearly a year older than most of the other students in her year.>>>

I don't think anybody thinks that Hermione is smart *because* she's 
nearly a year older than Harry. And, yes, there are exceptions to 
the cut-off - although I've never heard of any in the State sector. 
To go back to personal experiences, my own brother was doing Maths 
O'level questions when he was 10 - 6 years too early. There was no 
question of him jumping years, instead, the local borough advisor 
suggested to my parents that the State system could NOT accomodate 
him, and he was better off in the private system. To this extent, I 
think our State system is much more rigid than the US system.

It is possible that Hermione was always educated in the private 
sector, and was always a year in advance. This would still leave me 
with the question about how the Quill would have looked ahead. 
There's an easy enough answer - it's magic. The question which is 
never answered though is why Hermione's young age is never 
mentioned. It would be. Hermione is a little gauche when it comes to 
self-advertisement over her grades etc, and I cannot help thinking 
that even if her age wasn't generally known, Harry would know.

 <<< All of this points to a deadline sometime between September 19 
and mid-October.  While the available evidence doesn't give us an 
exact date, the evidence (Hermione being born in late September of 
1980 and Cedric being born in October of 1977) is stacked against a 
Sept. 1 cut-off, or a cycle that follows the calendar year.  Rather 
than being Flinty, JKR taking the trouble to confirm Hermione's 
birth year at this time seems, as someone else pointed out, more 
like her going out of her way to have Krum being taught to 
pronounce 'Hermione' in GoF. >>>

I agree that Hermione's birthday is now set in canon. I don't agree 
that evidence is "stacked against" a September 1st cut off. I would 
actually feel happier if the cut-off was placed around the Autumn 
Equinox, as it would explain why Hermione's late birthday wasn't an 
issue. But, I would still have to maintain that placing the cut-off 
here would have been an after-thought, to fit the facts that JKR had 
already provided us with.

Ali