2020 Census Deadline Extensions Act This bill extends certain deadlines for the 2020 decennial census. Specifically, the Department of Commerce must (1) complete the tabulation of total population by states, report the tabulation to the President, and make the tabulation public by May 1, 2021; and (2) complete tabulations of population related to state plans for legislative districting expeditiously, taking into account state deadlines, and report the tabulations by October 1, 2021.