Matariki, the Māori New Year will be recognised with a public holiday for the first time in June next year, but it won't always fall on the same date. Māori astronomers will use the positioning of the stars and moon to set the date of the public holiday for either a Friday or Monday each year. Tūhoe astronomer and chair of the Matariki Advisory Group Dr Rangi Mātāmua speaks to Susie Ferguson.