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

Other days

bounce

Bounce Day

carpenters

Carpenters Day

gallery

Gallery Day

azonto is acceptable

Azonto Is Acceptable Day

believe

Believe Day

Me Day

nail polish

Nail Polish Day

reading

Reading Day

pampering

Pampering Day

blanket fort

Blanket Fort Day