Historical clue formulations

• Super Bowl of 2023 — 2009-07-23
• Roman 57 — 2006-05-22
• Third year of Nero's reign — 2006-04-27
• Chapter 57 — 2005-02-22
• Mid first-century year — 2004-09-15
• Number of Heinz flavors in old Rome? — 1999-11-30
• Chapter 57 — 1996-10-22
• Heinz number, to Ovid — 1994-12-19