At what time is a witch/wizard categorized as one?

[Andrew]

No: HPFGUIDX 88870

Inge said
> Wondering also when one can know for sure if one's child is a 
> wizard/witch or not. Is it very early in the childs life or isn't 
> it until the letter from Hogwarts arrives?
> 
> In Harry's case it seems it was known wizardwide that he was 
> actually born to be a wizard since his name had been in the books 
> at Hogwarts since his birth.  But what about Neville? Didn't his 
> grandmother suspect him to be a squib?  And Hermione? Was she in 
> the books of Hogwarts since birth or didn't her name show up till 
> she turned 11?  So when does it come clear that a wizard is a 
> wizard?


Is there any canon that states the child must be 11 before recieving 
a letter? People are born all year round. I have a summer birthday 
like Harry and here I could either have been an old person for one 
grade, or a young person in the higher grade. With these 
complications, it is most likely that they would know if the child 
was a witch or wizard from birth. Do they really want all of that 
information open to the public? Wouldn't it most likely be tightly 
guarded; very valuable information. 

My thoughts
Andrew