Title: List of prime ministers of Canada by time in office
Content:  total of twenty-one years and one hundred fifty-four days. The prime minister's term begins upon appointment by the Governor General of Canada, usually after winning a general election, but sometimes after succeeding an outgoing prime minister of the same party. A prime minister stays in office until they resign, die or are dismissed by the Governor General. Two prime ministers have died in office (Macdonald and Sir John Thompson ). All others have resigned, either after losing an election or upon retirement. Theoretically, the Governor General can dismiss a prime minister, but that has never happened. The prime ministerial term is not 
Title: Prime Minister of Canada
Content:  of Commons and generally last for a shorter period of time. While the lifespan of a parliament is constitutionally limited to five years, a 2007 amendment to the Canada Elections Act, Section 56.1(2) limited the term of a majority government to four years, with election day being set as the third Monday in October of the fourth calendar year after the previous polling date The governor general may still, on the advice of the prime minister, dissolve parliament and issue the writs of election prior to the date mandated by the constitution or Canada Elections Act; the King–Byng Affair was the only time since Confederation that the governor general deemed it necessary to refuse his prime minister's request for a general vote. Following parliamentary dissolution, the prime minister must run in 
Title: List of prime ministers of Canada by time in office
Content:  the incoming and the outgoing prime ministers. A prime minister who holds office in consecutive parliaments is not re-appointed as prime minister for each parliament, but rather serves one continuous term. When a prime minister holds office in more than one parliament, it is customarily referred to as the prime minister's first government, second government, and so on. A majority government normally lasts around four years, since general elections for Parliament are normally held every four years. Minority governments generally last for a shorter period. The shortest minority government, Prime Minister Meighen's second government, lasted just under three months. A prime 
Title: List of prime ministers of Canada by time in office
Content:  prime minister remains in office without being sworn in again; the prime minister's tenure of office is continuous. If defeated in the election, the outgoing prime minister stays in office during the transition period, until the new prime minister takes office. All of that time is included in the total "Time in office". The first day of a prime minister's term is counted in the total, but the last day is not. For the first half century of Confederation, there were gaps between the term of an outgoing prime minister and the incoming prime minister. The shortest gap, two days, was 
Title: List of prime ministers of Canada by time in office
Content:  directly to the term of the House of Commons, which the Constitution sets as a maximum of five years from the most recent general election. A prime minister takes office after winning an election, and resigns after losing an election, but the term in office does not match up directly to the term of the Parliament. An incoming prime minister will normally take office a few weeks after the election, and an outgoing prime minister will usually stay in office for a few weeks after losing the election. The transition period and the date for the transfer of office are negotiated 
Title: List of prime ministers of Canada by time in office
Content:   This article is a list of the prime ministers of Canada by their time in office. The list starts with Confederation on July 1, 1867, and the first prime minister, Sir John A. Macdonald. It includes all prime ministers since then, up to the current prime minister, nor do they have term limits. Instead, they can stay in office as long as their government has the confidence of a majority in the House of Commons of Canada under the system of responsible government. Under this system, Prime Minister Mackenzie King was Canada's longest-serving prime minister, holding office in three non-consecutive terms for 
Title: List of prime ministers of Canada by time in office
Content:  Campbell (1993) and Paul Martin (2003) all succeeded to the office in this way. The new prime minister may continue to govern in the parliament called by the previous prime minister, but normally calls an election within a few months. (Prime Minister Meighen was the exception, governing for over a year before calling an election.) In those cases, the time before and after the election is counted as one government for the purposes of this table. When a general election is called, the current prime minister stays in office during the election campaign. If the prime minister's party wins the election, 
Title: House of Commons of Canada
Content:  general elections. The time chosen reflects political considerations, and is generally most opportune for the prime minister's party. However, no parliamentary term can last for more than five years from the first sitting of Parliament; a dissolution is automatic upon the expiry of this period. Normally, Parliaments do not last for full five-year terms; prime ministers typically ask for dissolutions after about three or four years. In 2006, the Harper government introduced a bill to set fixed election dates every four years, although snap elections are still permitted. The bill was approved by Parliament and has now become law. 
Title: Prime Minister of Canada
Content:  The prime minister serves At Majesty's pleasure, meaning, the post does not have a fixed term, and that once appointed and sworn in by the governor general, the prime minister remains in office until they resign, are dismissed, or die. In practice, under the system of responsible government, the prime minister (by convention) resigns should they lose the confidence of the elected House of Commons. This can happen if the government loses an important vote, such as on the budget (loss of supply), or more explicitly if a motion of no confidence is passed. A loss of confidence is rare if the government enjoys a majority. Majority governments typically last about four years (since elections are normally held every four years). Minority governments are more liable to lose the confidence of the 
Title: List of prime ministers of Canada by time in office
Content:  Macdonald and Alexander Mackenzie in 1873: Macdonald resigned office on November 5, 1873, and Mackenzie was appointed on November 7. The longest gap, ten days, was upon the death of Macdonald on June 6, 1891. Prime Minister Abbott did not take office until June 16, 1891. The last time there was a gap, of four days, occurred between Laurier and Robert Borden: Laurier resigned effective October 6, 1911, and Borden took office on October 10. There have been no gaps in office since that transition, with the new prime minister taking office the day after the former prime minister leaves office.

Question: how long prime minister stay in office canada?
Answer: four years.