Chatham Islands Anniversary Day is observed on the Chatham Islands archipelago in New Zealand, celebrated on the Monday closest to November 30. This public holiday commemorates the first landing of Europeans on the islands, specifically marked by the arrival of crew members from the HMS Chatham on November 29, 1791. The Chatham Islands, located about 800 km east of New Zealand’s South Island, were first settled by the Moriori, a Polynesian ethnic group, around the 15th century. The holiday serves to recognize the historical significance of European contact and the subsequent impacts on the Moriori population, including significant loss of life due to introduced diseases and later conflicts with Māori settlers. Today, the local economy is largely based on fishing and farming, and the holiday provides a long weekend for residents, who are primarily of European, Māori, or mixed ancestry.