51 Sets of Presidential Election Rules in the United States

 I can't wrap my head around this but this is the reality for our neighbours to the South.

The National Conference of State Legislatures in the United States has prepared an explanation called After the Voting Ends: The Steps to Complete an Election:

"An election isn’t over when the polls close. It’s over when election administrators complete their postelection activities and the election results are certified. As with everything else related to elections, state law governs these postelection processes—and there are 51 models. (The states plus Washington, D.C.)."

There are explanations for how and where and when different states count ballots, including mail-in ballots; deadlines for certifying the results; the rules for contesting the results; rules for interpreting the intent of voters whose ballots are marked ambiguously or incorrectly completed, etc.