Tuesday marks the "safe harbor" date -- a provision inscribed in federal law that requires states to resolve all election-related disputes before the Electoral College meets in order for the results to be considered "conclusive."
The safe harbor date always falls six days before the Electoral College gathers to cast votes for president and vice president. With the Electoral College meeting set for Dec. 14 this year, that puts the safe harbor date on Dec. 8.
The deadline for states to certify their election results essentially insulates states from legal challenges down the road when Congress counts the electoral votes in early January (and members of the House and Senate are able to contest a slate of electors). Those electors certified by the safe harbor date are considered binding -- making them extremely difficult to dispute in the courts.
"If election results are contested in any state, and if the state, prior to election day, has enacted procedures to settle controversies or contests over electors and electoral votes, and if these procedures have been applied, and the results have been determined six days before the electors’ meetings, then these results are considered to be conclusive, and will apply in the counting of the electoral votes," a report on the Electoral College from the Congressional Research Service reads. "This date, known as the 'Safe Harbor' deadline, falls on December 8 in 2020."
Don’t expect much fanfare on Tuesday. The date is marked by little beyond remaining states submitting "Certificates of Ascertainment" to the National Archives -- a formal document certifying their state’s electors for either Donald Trump or Joe Biden.
"The governor of any state where there was a contest, and in which the contest was decided according to established state procedures, is required (3 U.S.C. §6) to send a certificate describing the form and manner by which the determination was made to the Archivist as soon as practicable," the report continues.
The Archivist of the United States has received certificates from at least 26 states -- including five that are in the president’s crosshairs for post-election legal challenges: Arizona, Georgia, Michigan, Pennsylvania and Wisconsin.
In Nevada, another battleground state that has seen overtime challenges, the election results were certified on Nov. 24 and Democratic Gov. Steve Sisolak signed the certificate on Nov. 25. A spokesperson for Sisolak did not respond to ABC News' multiple inquiries on Monday about whether the state submitted documentation to the National Archives, which is not yet posted to the site.
Some states may take longer to send in the paper record since they are required to prepare them "as soon as practicable" but most deliver it in time to be posted online before next week's virtual gathering.
Even with one of the final roadblocks coming on Tuesday, the Trump campaign legal team is keeping up their exacerbated efforts to overturn Biden's victory.
Jenna Ellis, who is a senior legal adviser to the Trump campaign, told Fox Business, "Although we have the safe harbor deadline today, and we have the meeting of the Electoral College next week on Dec. 14, the ultimate date of significance is Jan. 6."
"While we are on some tight constitutional deadlines, we still have plenty of time to make sure the election and the outcome is free and fair for all Americans," she added.
Ellis was referring to when the electoral process heads to Congress in early January, but for any state that chooses its electors by Tuesday (Dec. 8), Congress must count those electoral votes next month.