January 2020: Primaries and caucuses begin
The traditional primaries and caucuses will begin in Iowa and New Hampshire, as states decide upon candidates for both the Democratic and Republican nomination for the presidency.
Super Tuesday will occur in early March, when several states decide on one day, often pushing the respective winners to the fore. However, the contest can run on until the final primaries in June, and even to the conventions across the summer, if there is a deadlock.
Summer 2020: Conventions
The Democrats will hold their convention between 13-16 July, in Milwaukee and decide upon their candidate for the presidency.
Because they currently hold the White House, the Republicans will hold their convention after the Democrats, although they have not yet fixed a date. It will be held in the city of Charlotte, North Carolina.
Unless some major internal party conflict emerges, it is likely this convention will support President Trump to contest the presidency for a second term.
3 November 2020: Presidential election
US voters will go to the polls to decide between re-electing Donald Trump for a second term, or choosing whoever emerges as his Democratic opponent.
The election will be held at the same time as elections to the Senate and the House of Representatives.