1968 Richard M. Nixon was nominated for president at the Republican National Convention in Miami Beach. Later that day, Nixon chose Maryland Governor Spiro T. Agnew to be his running mate
1973 Vice President Spiro T. Agnew branded as “damned lies” reports he had taken kickbacks from government contracts in Maryland and vowed not to resign. He eventually did resign
1974 US President Richard Nixon announced his resignation, which would take effect at noon the following day

Funny - All on the same day.