Dates for DNC: 2016: January 1, 2015 to August 31, 2016 // 2020: January 1, 2019 to August 31, 2020 /// Dates for Biden/Clinton: 2016: January 1, 2015 to August 31, 2016 // 2020: January 1, 2017 to August 31, 2020