Nah, this is a relatively new public holiday that we've only been observing since 2022. It's called Matariki. Here's the summary:
Historically, Matariki was usually celebrated for a period of days during the last quarter of the moon of the lunar month Pipiri (around June). The ceremony involved viewing the individual stars for forecasts of the year to come, mourning the deceased of the past year, and making an offering of food to replenish the stars. Some Māori use the rise of Puanga (Rigel) or other stars to mark the new year.
Celebration of Matariki declined during the 20th century, but beginning in the early 1990s it underwent a revival. Matariki was first celebrated as an official public holiday in New Zealand on 24 June 2022.
It was originally proposed to replace our Queen's Birthday public holiday, but in the end we got both.