A fixed-term election is an election that occurs on a set date, and cannot be changed by incumbent politicians other than through exceptional mechanisms if at all. Fixed-term elections are common for directly elected executive officers, such as directly elected mayors, governors and presidents, but less common for prime ministers and parliaments in a parliamentary system of government. Examples The Australian Senate has a semi-fixed term that can be cut short only by a double dissolution under Section 57 of the Australian constitution, used if there is a prolonged deadlock over a bill supported by the Australian House of Representatives. While the term itself is fixed, the election date can be shifted with the government having a ten month window it can schedule the election on. After a double dissolution election, to restore rotation, newly elected Senators' terms are backdated to the previous 1 July so that they serve less than three or six years. Since the Australian House of Representatives has a maximum term of only three years but no minimum term, elections for the two houses can become desynchronised, resulting in separate elections for each house. However, this has not happened since 1970. The Australian states and territories of New South Wales, South Australia, Victoria, Queensland, the Northern Territory and the Australian Capital Territory (ACT) have semi-fixed terms in that dissolution at any time in mid-term is allowed only to resolve a serious deadlock. Elections to the European Parliament are considered the second largest democratic elections in the world and occur every five years on a weekend in June. Each country is relatively free to set its own election rules and each chooses one out of the four days of the selected weekend to hold its election. In Hong Kong, according to the Hong Kong Basic Law, the Chief Executive is elected every five years and the Legislative Council is elected every four years. Under some circumstances the Chief Executive may dissolve the Legislative Council, and under some other circumstances the Chief Executive is obliged to resign. In 2005 it was resolved that if the office of the Chief Executive is left vacant, the successor serves only the remainder of the term of his or her predecessor. Elections in Norway take place every two years, alternating between parliamentary and local elections. Norway is unusual in that the legislature cannot be dissolved early (a trait it shares with the