Historical clue formulations

• Sudden and unexpected — 2026-09-22
• Out-of-the-blue — 2024-09-07
• Sudden — 2023-07-09
• Brusque — 2023-05-31
• Unceremonious — 2022-02-19
• Sudden — 2018-06-01
• Sudden — 2010-04-04
• Sudden — 2009-12-28
• Short — 2009-08-18
• Brusque — 2008-02-11
• Sudden — 2007-04-09
• Short — 2003-08-09
• Sudden — 1999-08-08
• Curt — 1999-05-04
• Steeply inclined — 1995-05-11