Daylight saving time (DST) is currently observed in nine of ten provinces and two of three territories in Canada, but with exceptions in several provinces and Nunavut. Most of the province of Saskatchewan, despite geographically being in the Mountain Time Zone, observes year-round Central Standard Time (CST). In 2020, the territory of Yukon abandoned seasonal time change to permanently observe year-round Mountain Standard Time (MST). Under the Canadian Constitution, laws related to timekeeping are a provincial or territorial matter.