Australian states and territories observe the Queen's Birthday on the second Monday in June, except in Western Australia and Queensland. As Western Australia celebrates Western Australia Day (formerly known as Foundation Day) on the first Monday in June, the Governor of Western Australia each year proclaims the day on which the state will observe the Queen's Birthday, based on school terms and the Perth Royal Show. There is no firm rule to determine this date, though it is usually the last Monday of September or the first Monday of October. Some regional areas of Western Australia celebrate the Queen's Birthday public holiday on alternative days for locally significant dates or events. In 2012, Queensland celebrated the holiday in October, as the June holiday was reserved to mark Elizabeth II's Diamond Jubilee as Queen of Australia, after which the holiday then for three years reverted to its traditional date in line with the other eastern Australian states. However, starting in 2016, Queensland celebrates the holiday on the first Monday of October.