Oops, it doesn't look like 'historical centres historical centres day' is a national day..

Other days

bounce

Bounce Day

boyfriend

Boyfriend Day

lumpy rug

Lumpy Rug Day

get funky

Get Funky Day

nail polish

Nail Polish Day

comfy

Comfy Day

boy friend

Boy Friend Day

pick me

Pick Me Day

lost sock memorial

Lost Sock Memorial Day

ride the wind

Ride The Wind Day