Oops, it doesn't look like 'dex complainers and pokemon fans on the release day' is a national day..

Other days

hiv awareness

Hiv Awareness Day
azonto is acceptable

Azonto Is Acceptable Day
martini

Martini Day
my little pony

My Little Pony Day
one

One Day
blanket fort

Blanket Fort Day
youth

Youth Day
african immigrant and refugee hiv and hep awareness

African Immigrant And Refugee Hiv And Hep Awareness Day
lost sock memorial

Lost Sock Memorial Day
reading

Reading Day