Oops, it doesn't look like 'best friend post a picture of your boyfriend day' is a national day..

Other days

prosecco

Prosecco Day

nail polish

Nail Polish Day

Me Day

lisp

Lisp Day

bounce

Bounce Day

self care

Self Care Day

ask out your crush

Ask Out Your Crush Day

boyfriend

Boyfriend Day

pumpkin

Pumpkin Day

azonto is acceptable

Azonto Is Acceptable Day