Oops, it doesn't look like 'letter to an elder day' is a national day..

Other days

martini

Martini Day

cuddle up

Cuddle Up Day

eat what you want

Eat What You Want Day

ruby

Ruby Day

special education

Special Education Day

buddy

Buddy Day

Me Day

carpenters

Carpenters Day

ride the wind

Ride The Wind Day

self care

Self Care Day