Potter Fanaticism and days to celebrate

[Martha]

How about - you might be a Harry Potter fanatic when you get excited 
about February 1st being, apparently, "St Severus's Day", and you 
resolve to make potions to celebrate, even though St Severus's Day 
has nothing to do with potion making whatsoever? ;-)

http://www.123greetings.com/events/february2004.html

(Third thing down on February 1st.)

Other festivals you may be interested in celebrating during the month 
of February include, as you can see, Thumb Appreciation Day (18th), 
Banana Bread Day (23rd), Homemade Soup Day (4th), Thanks For A Great 
Valentine's Day Day (15th), Clean Out Your Computer Day (9th), and my 
personal favourite: Blame Someone Else Day (13th).

So... are these real festivals? Who chooses them? Could we make, say, 
February 17th Harry Potter For Grown-Ups Day, where everyone gives us 
gifts? Or could I declare May 30th, which happens to be my birthday,  
International Martha Day? 

Just a few thoughts...

~ Martha, happily contemplating how cool International Martha Day 
would be