When are primaries and debates? Key dates in the 2020 presidential election calendar

Voters will cast ballots in the 2020 president race in the fall, but primary elections across the US to select the Democratic nominee, along with a host of local elections, have been postponed or moved or held under potentially dangerous conditions as the coronavirus pandemic has altered the course of candidates' campaigns.

Following those contests and nomination convention, the Democratic nominee will participate in presidential debates against Donald Trump this fall.

Republican parties in several states have cancelled their party primaries, presuming the incumbent will be on the ballot.

Here's an amended schedule of key election events — and a recap of what has happened so far — in the 2020 race.

14 January

Five candidates qualified for the seventh Democratic debate, which will be hosted by CNN and The Des Moines Register at Drake University in Des Moines, Iowa. On the stage will be Joe Biden, Pete Buttigieg, Amy Klobuchar, Bernie Sanders and Elizabeth Warren.

3 February

Bernie Sanders won the largest share of votes but was narrowly defeated by Pete Buttigieg for state delegate equivalents in the Iowa caucus, which captured the first votes cast in the Democratic primary race. After a chaotic release of the vote totals that ultimately led to the resignation of the state's Democratic party chair, there was heavy scrutiny over the results of the primary season's opening contest, leading to speculation for the candidates' futures as larger state primaries followed, and as the campaigns — and donors — strategised ahead of the election's crucial next few months.

7 February

ABC, WMUR and Apple News at St. Anselm College in Manchester, New Hampshire hosted the eighth Democratic primary debate.

11 February

After winning the state in a landslide in 2016, Senator Sanders won the popular vote in the New Hampshire primary, followed by a second-place finish from Pete Buttigieg and a surprise third from Amy Klobuchar. Andrew Yang, Michael Bennett and Deval Patrick later dropped out.

19 February

NBC News, MSNBC and The Nevada Independent hosted the ninth Democratic primary debate in Las Vegas, Nevada.

22 February

Senator Sanders won the Nevada Democratic caucus, which offered a glimpse of candidates' success outside the East Coast in a key state with a large Latino voting population. The senator received 24 delegates to the former vice president's nine. No other candidate passed the threshold for delegate consideration.

25 February

CBS News, Twitter and the Congressional Black Caucus Institute at The Gaillard Center hosted the 10th Democratic debate in Charleston, South Carolina.

29 February

Joe Biden won nearly 49 per cent of the popular vote in South Carolina, the first southern state to enter the primary contest, serving as a test of the strength of African-American support among the Democratic candidates. The former vice president captured 39 delegates to Senator Sanders 15. Following the primary, Tom Steyer — who came in third place — dropped out of the race. Republicans cancelled their party's primary in the state, with the incumbent president as the presumed nominee.

3 March

Fifteen states across the US held primary contests on Super Tuesday, including California, which has the largest delegate count in the US, with 415 delegates pledged to the Democratic nominee, and Texas, the second-largest delegate trove, with 228 delegates pledged to the Democratic nominee. After Pete Buttigieg and Amy Klobuchar withdrew from the race and endorsed Joe Biden, his resurgent campaign won nine states, including Texas, while Bernie Sanders won California and three other states. After disappointing finishes throughout the primary, including no victories on Super Tuesday, Elizabeth Warren ended her campaign two days later. Billionaire Michael Bloomberg also dropped out and endorsed Biden.

3-10 March

US citizens living abroad cast their votes in the Democrats Abroad primary. Bernie Sanders received nearly 60 per cent of the vote, securing nine delegates. Joe Biden received 22 per cent of the vote and four delegates.

10 March

As the coronavirus pandemic gripped the US, campaign events and rallies were cancelled, though voting was still on in in Idaho, Mississippi, Missouri, North Dakota, Washington and Michigan, a crucial battleground state for the two-man race. While Bernie Sanders won North Dakota, Joe Biden won the remaining states, with a narrow victory in Washington state.

15 March

The public health crisis framed the election's unprecedented 11th debate, hosted by CNN and Univision and giving Joe Biden and Bernie Sanders and audience-free platform from Phoenix.

17 March

Ohio postponed its primary to 2 June as Arizona, Florida and Illinois held their elections as states across the US began ordering residents to stay at home and public health warnings urged people to avoid crowds, beginning a series of controversial election events in the thick of the crisis. Joe Biden ultimately won 296 delegates by sweeping the three states. Tulsi Gabbard ended her campaign two days later.

4 April

There are Democratic and Republican primaries in Louisiana and Wyoming. Alaska and Hawaii will host Democratic primaries, but the GOP cancelled the party's primaries in those states.

7 April

Wisconsin held its Democratic party despite calls from voters and the state's governor to postpone. Republican lawmakers and conservative majorities on the state and US supreme courts ultimately blocked those efforts, which also prevented absentee or mail-in ballots from being cast at a later date, forcing thousands of voters into a small number of open polling sites during the pandemic. Joe Biden ultimately won in the state, as Bernie Sanders's supporters and other critics painted the election as illegitimate. The next day, the senator announced he was suspending his campaign.

26 April

Puerto Rico holds its Democratic primary.

2 May

There are primaries in Guam and Kansas.

12 May

There are primary elections in Nebraska and West Virginia.

19 May

Oregon hold its primary election.

22-25 May

The Libertarian Party hosts its annual convention in Austin, Texas. Delegates will choose their candidate for the ballot from among the party's 14 declared candidates. Organisers say that due to the coronavirus crisis, it is "still too early to make any 'permanent' plans related to the implementation" of the event.

2 June

There are primaries in Montana, New Jersey, New Mexico, South Dakota and Washington DC. Connecticut, Delaware, Indiana, Maryland, Pennsylvania and Rhode Island will also hold their primaries, which were postponed due to the coronavirus crisis.

6 June

The US Virgin Islands and Puerto Rico hold their primaries.

20 June

Louisiana holds its Democratic primary, which was postponed from April.

23 June

Kentucky and New York hold their Democratic primaries, which moved from April

9-12 July

The Green Party holds its annual convention in Detroit, Michigan where delegates will select its candidate; formally recognised candidates include party co-founder Howie Hawkins and Dario Hunter of New Jersey.

17-20 August

Democratic delegates will convene in Milwaukee to nominate their candidate during the Democratic National Convention. The event was originally scheduled for July but was postponed due to the coronavirus crisis.

24-27 August

Republicans will hold their annual nominating convention in Charlotte, North Carolina.

29 September

The University of Notre Dame hosts the first 2020 presidential debate.

7 October

Republican and Democratic nominees for vice president will debate at the University of Utah.

15 October

The second presidential debate will take place at the University of Michigan.

22 October

Belmont University in Nashville, Tennessee will host the third and final presidential debate.

3 November

Election Day — voters across the US will participate in a general election to select the next president, along with other candidates that appear on local ballots.

14 December

Electoral college representatives meet in state capitols to formally cast votes.

6 January 2021

Congress enters electoral votes into the record, and the Senate president announces vote tallies.

20 January 2021

Inauguration Day — the president-elect will be formally sworn into office.