Oops, it doesn't look like 'air and space museum day' is a national day..

Other days

me

Me Day
donate your hair

Donate Your Hair Day
special education

Special Education Day
prosecco

Prosecco Day
boba

Boba Day
cursing

Cursing Day
self appreciation

Self Appreciation Day
chocolate milkshake

Chocolate Milkshake Day
tell ur crush you like them

Tell Ur Crush You Like Them Day
bow tie

Bow Tie Day