Historical clue formulations

• Lunacy — 2025-04-27
• Unwise undertaking — 2010-12-15
• Huge mistake — 2006-07-10
• Unwise undertaking — 2004-05-29
• Unreason — 2003-09-05
• Imprudence — 1997-08-23
• Bad move — 1996-12-11