Snape as the One in Prophecy

[mompowered]

No: HPFGUIDX 136593

--- In HPforGrownups at yahoogroups.com, "potioncat" <willsonkmom at m...> 
wrote:
<snip>
> Potioncat:
> Eileen finds herself in the family way, her wizard boyfriend is no 
> where to be found. She marries a willing, but ignorant Muggle and 
> Severus is born just short of 8 months after the wedding. (as the 
7th 
> month dies)
<snip>

Although it was said on this list, I think, that Snape's birthday was 
in January.  How do we know about Snape's birthday?  Was it in a JKR 
interview, or in one of the books (I can't remember)?

Cheryl