Northland Anniversary Day, also known as Auckland Anniversary Day, is observed in the northern half of New Zealand's North Island, particularly throughout the historic province of Auckland. This public holiday is celebrated annually on the Monday closest to January 29, with the date for 2026 set for January 26. The day commemorates the arrival of William Hobson, the first Governor of New Zealand, who played a significant role in the establishment of British sovereignty and the signing of the Treaty of Waitangi in 1840. Typical customs include public celebrations and the closure of government offices, as it marks the anniversary of the colony's founding. The holiday was first established in 1842, when Hobson declared a general holiday to honor the colony's second anniversary.