Oops, it doesn't look like 'thank a troop day' is a national day..

Other days

kale

Kale Day
china

China Day
bubble bath

Bubble Bath Day
artists

Artists Day
bow tie

Bow Tie Day
kiss a brunette

Kiss A Brunette Day
boba

Boba Day
lumpy rug

Lumpy Rug Day
book

Book Day
reading

Reading Day