Oops, it doesn't look like 'particle accelerator open day' is a national day..

Other days

self care

Self Care Day
raise awerness of zeus

Raise Awerness Of Zeus Day
artists

Artists Day
emoji

Emoji Day
cuddle up

Cuddle Up Day
self appreciation

Self Appreciation Day
kiss a ginger

Kiss A Ginger Day
blanket fort

Blanket Fort Day
carpenters

Carpenters Day
kiss a brunette

Kiss A Brunette Day