The PiDay is the national day of Pi ! Each year, on march, 14th (3/14, ha ha ha), fans of Pi meet to promote and celebrate our favorite constant. Here are a few pictures, videos and amazing events per year. Then a few pictures of my own modest PiDays, (click on pictures to get a bigger one). If you have contributions or links, do not hesitate, please contact me ! I'm just starting to compile stuff and filling this page, many other anecdotes/pictures/videos to come in the next few months !
About the Pi Day
The first Pi Day celebration was held at the San Francisco Exploratorium in 1988, with staff and public marching around one of its circular spaces, then consuming fruit pies (Wikipedia). The museum has since added pizza to its Pi Day menu. The founder of Pi Day was Larry Shaw (on the right), a nowretired physicist at the Exploratorium who still helps out with the celebrations.
Theoretically, the celebration exact time is 3/14 at 1:59pm (the socalled Pi Minute !) but many other interpretations have been proposed and the crazier, the funnier regarding this event anyway ! For instance, some people have proposed to celebrate the Pi Day on July 22 because written in the European date format as 22/7, it is an approximate value of pi closer than 3/14 !
The american congress even passed a nonbinding resolution on march 12th, 2009(HRES244) recognizing the march 14th as the national day of Pi ! Yes, absolutely, see the proof here.
Finally, me and my website love the Pi Day, especially when I see the audience of Pi314.net on march 14th :) (in 2011)
In the world !
2013
TatooPi check by Emilie and friends! 



Pi in the eyes (of my little girl Roxane) 
"A big slice of Pi": a huuuuuuge poem by the Pienthusiast Marc Umile (file .doc) 

A Big Slice of Pi 
2011
those "Pies" smell yummy, ! (galery of djwtwo) 
I hate Pi day ! (spikedmaths) 
PiDay at Princeton: the Geek Freak WeekEnd, I love it:) 
dans l'ordre
Caramelbottomed Guiness Chocolate Pi ! 
Maple Pecan Pi 
MangoPeach Pi 
Apple Pi 
Lemon and orange layered cheesecake Pi 
Cherry Pi 






A halfmarathon as loops in both directions and nicely dubbed River Rotation, beautiful idea ! 
A computation contest between... an old calculator and an Apple II ! And 41 hours to compute 1000 digits of Pi with the Apple computer, tough time for it ! 


2010
On Google absolutely ! 
On Wikipedia (the image might be older but who cares !) 
Zandar Blog
(click on the picture to see it bigger) 






San Francisco Exploratorium  The necklace in Pi digits, what a great idea ! 





2009
Song (Video, English): Oh number Pi ! 
The friends of number Pi (german)
Each year, this nice association organizes events around Pi with good mood !) 
PiDay.org
(click on the picture to see it bigger) 
Classic but fun 





Freaking News  Pi Day Picture Contest  Each year, a contest of photo(shop) on Pi for the PiDay, great !!! 
Pi Day on Second life  Arf, not very crowded... 
Mathematicians Pictures  Official PiDay Button 



2008
2007
Song (Video, English): Pi Day Song ! 
Song (Video, English): Pi Day Song ! 
The friends of number Pi (german). A painting of Michael Franke 
American Pie, or how to learn digits while singing 
This is huge... it's bad, it's out of tune, it's saturated, it's unbearable !! ;) 




Qwantz  Dinosaur Comics
(click on the picture to see it bigger). It moderately funny according to me... 
Pineamelon  Manga 




2006
2005
Pi Day in a switzserland class room (Bez Endingen), lots of activities around Pi 





At home !
2010
2009
And from a friend on the Internet (Yves de Lombaerde), a crepe/pancake (circular of course !) dated from the Piday !
2007
2004 in my lab
 2  3
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