Closest New Zealand has is Waitangi Day, which is February 6th. On this day in 1840 the Maori signed the Treaty of Waitangi with the British making New Zealand a British colony. Since then it has caused significant social and political issues (I know far too much on the subject). What usually happens on this day is that I work (as university doesn't go back for another couple of weeks) and get paid time and a half plus day in lieu. Most people use this day as a big piss up or an excuse to go to the beach, with many uninformed racist people complaining about how the Maori are trying to take all the taxpayers money. It's always fun when I argue with those people, mostly because their circular logic doesn't stand up.
Politically, what usually happens is the Prime Minister of the day goes to the Marae (meeting house) in Waitangi and sometimes the Maori protest. It's always interesting when protests happen. The media usually highlights the most relevant political issues of the day and questions what the government is going to do about it. Maori party has their spiel on what they'd like to see happen.
On the plus side, it always seems to be a perfect sunny day on Waitangi day, even if most of the time I am working.