Oops, it doesn't look like 'heartbreak on valentines day' is a national day..

Other days

reading

Reading Day
singles

Singles Day
aloxolt

Aloxolt Day
self appreciation

Self Appreciation Day
azonto is acceptable

Azonto Is Acceptable Day
blanket fort

Blanket Fort Day
bounce

Bounce Day
my little pony

My Little Pony Day
lost sock memorial

Lost Sock Memorial Day
believe

Believe Day