{|style="float: right; margin-left:2em" class="wikitable"
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!Longest presidency
!Shortest presidency
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The length of a full four-year term of office for a president of the United States usually amounts to 1,461 days (three common years of 365 days plus one leap year of 366 days). The listed number of days is calculated as the difference between dates, which counts the number of calendar days except the first day (day zero). If the first day were included, all numbers would be one day more, except Grover Cleveland would have two more days, as he served two full nonconsecutive terms.<!--Do not add Donald Trump, as he has yet to complete his second nonconsecutive term-->
Of the individuals elected president, four died of natural causes while in office (William Henry Harrison, Zachary Taylor, Warren G. Harding, and Franklin D. Roosevelt), four were assassinated (Abraham Lincoln, James A. Garfield, William McKinley, and John F. Kennedy), and one resigned from office (Richard Nixon).
William Henry Harrison spent the shortest time in office, while Franklin D. Roosevelt spent the longest. Roosevelt is the only American president to have served more than two terms. Following ratification of the Twenty-second Amendment in 1951, presidents—beginning with Dwight D. Eisenhower—have been ineligible for election to a third term or, after serving more than two years of a term to which some other person was elected president, to a second term. The amendment contained a grandfather clause that explicitly exempted the incumbent president, then Harry S. Truman, from the new term limitation.
While there have been 47 presidencies in the nation's history, only 45 people have been sworn into office; Grover Cleveland and Donald Trump were elected to two nonconsecutive terms.
Presidents by time in office
{| class="wikitable sortable"
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! data-sort-type="number" | Rank !! data-sort-type="text" | President !! class="unsortable" | Length<br/><small>in days</small> !! Order of presidency !! class="unsortable" | Number of terms
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| 1 || nowrap|
|
| || Three full terms; died into fourth term
|-
| rowspan=12|2<br>tie ||
|
| || Two full terms
|-
|
|
| || Two full terms
|-
|
|
| || Two full terms
|-
|
|
| || Two full terms
|-
|
|
| || Two full terms
|-
|
| 2,922
| || Two full terms (nonconsecutive)
|-
|
|
| || Two full terms
|-
|
|
| || Two full terms
|-
|
|
| || Two full terms
|-
|
|
| nowrap| || Two full terms
|-
|
|
| || Two full terms
|-
|
|
| || Two full terms
|-
| 14 ||
|
| || Two full terms
|-
| 15 ||
|
| ||Succeeded to one partial term (), followed by one full term
|-
| 16 ||
|
| ||Succeeded to one partial term (), followed by one full term
|-
| 17 ||
|
| || Succeeded to one partial term (), followed by one full term
|-
| 18 ||
|
| || One full term; resigned into second term
|-bgcolor=#FFDDDD
| 19 ||
|
| || One full term, currently serving second (nonconsecutive) term
|-
| 20 ||
|
| ||Succeeded to one partial term (), followed by one full term
|-
| 21 ||
|
| || One full term; assassinated: died into second term, days after being shot
|-
| 22 ||
|
| || One full term; assassinated: died into second term, day after being shot
|-
| rowspan="12"|23<br>tie ||
|
| || One full term
|-
|
|
| || One full term
|-
|
|
| || One full term
|-
|
|
| || One full term
|-
|
|
| || One full term
|-
|
|
| || One full term
|-
|
|
| || One full term
|-
|
|
| || One full term
|-
|
|
| || One full term
|-
|
|
| || One full term
|-
|
|
| || One full term
|-
|
|
| || One full term
|-
| 35 ||
|
| || One full term
|-
| 36 ||
|
| || Succeeded to one partial term ()
|-
| 37 ||
|
| || Succeeded to one partial term ()
|-
| 38 ||
|
| ||Succeeded to one partial term ()
|-
| 39 ||
|
| || Assassinated: died into term
|-
| 40 ||
|
| || Succeeded to one partial term ()
|-
| 41 ||
|
| ||Succeeded to one partial term ()
|-
| 42 ||
|
| ||One partial term; died into term
|-
| 43 ||
|
| ||One partial term; died into term
|-
| 44 ||
|
| || Assassinated: died into term; days after being shot
|-
| 45 ||
|
| ||One partial term; died into term
|}
Notes
See also
- List of vice presidents of the United States by time in office
- Lists of presidents by time in office
References
External links
- Millercenter.org, American President: A Reference Resource
- Whitehouse.gov, The Presidents