Historical clue formulations

• Political convention attendees: Abbr. — 2023-06-23
• Some convention-goers: Abbr. — 2023-06-06
• Conventioneers: Abbr. — 2014-08-09
• Singers Shannon and Reeves — 2012-12-05
• Pol. convention attendees — 2009-11-14
• Singers Shannon and Reeves — 1996-09-20