Labour Day (but I like the name International Worker's Day better).

International Talk Like a Pirate Day, the Pastafarian religious holiday celebrated on September 19.

My birthday. Send me gifts, everyone.

Fat Thursday. Wiki says it's Christian holiday but in Poland no one really associates it with anything religious, everyone just eats pączki.

Día de los Muertos, because of the amazing art at the very least. Plus, who wouldn't want a second Halloween of sorts? (I know the reasons to celebrate are very different)

Also, Earth Day and Arbor Day, because our trees and planet are awesome.

Wednesday. It should always start or end a long weekend. (Of course this would be a paid holiday)

May day!

“Respect for the aged” day in Japan.

Maybe "wish" isn't a fully accurate word, but I have a few that come to mind.

Sibling Day. Like Valentine's Day, Father's Day, or Mother's Day, but for your siblings. I have had a fluctuating bond with my siblings and this would've been a nice thought.

Friendship Day. We technically celebrate it, but in a rather underwhelming way. There's an annual "friendship festival", but when you go there, they say something like "happy day of friendship between our nation and our Northern neighbors", so it's in a different sense. Might as well go the whole way.

Deganawida Day. This one requires explaining. One day from now, 882 years ago, a great nation here was founded, an empire of righteousness, health, and power. It was of course conquered, but it still culturally resonates. The name of the holiday would be after its founder and the form of celebration would be similar to a day of interpersonal goodwill and local patriotism. Considering the way society is, it would be a nice fix. If added to the calendar, it would also give the lonely month of August its own holiday.

Michaelmas. I grew up with Michaelmas. I still observe it. Why do we shirk it? Cuz some guy who famously nailed a decree on a church door said so? I'm more annoyed people actively avoid it.

Hawaiki Day or whatever you want to call it. I'm surprised we have a day of the year for Christopher Columbus because the Italians voted it in and one for Leif Erickson because the Norse-loving folk voted it in and not one for the Polynesians who discovered South America before the Vikings discovered North America. It's only fair.

International Cat Day (August 8th)

and Black Cat Appreciation Day (August 17th).

National Test Your Backups day. So much time and money lost because people either don't backup their data or assume they have when they have not. (Ok it's not a real holiday but it should be)

Everybody should get carnival.

Australian here. Halloween.

Earthday. Not just on its own merits (which are substantial) but because there is a general lack of US federal holidays on that side of the calendar.

Fête Nationale / St Jean-Baptiste

There are over 2 million Franco Americans in New England alone. And yet, I seem to be one of the few who remembers our history, nevermind our language. This is not an indictment, we've had to adapt to survive and avoid persecution.

But still we're allowed to be proud, we're allowed to be seen, and I'd love to live long enough to see our diaspora celebrate our roots and our present on both sides of the border

Et bien sûr, vive le Québec libre

Towel day!

Arbor Day! Trees ftw!

Not the Father’s Day?

Obviously: 春节 /s

Pride month. It should be a federal holiday.