more information if you do not know https://www.google.com/search?q=pi+day&rlz=1C1GCEA_enUS1041US1041&oq=pi+day&aqs=chrome..69i57j69i61l3.2593j0j7&sourceid=chrome&ie=UTF-8&safe=active&ssui=on
why it is 1 day earlier anyways?