Historical clue formulations

• It's unlikely to happen again — 2026-07-29
• Happy accident — 2017-09-11
• Sushi offering — 2014-09-27
• Stroke of luck — 2005-09-14
• Hole in one, assuredly — 2004-11-21
• Result of careful planning it's not — 2000-11-22
• Bit of serendipity — 1999-06-04