Historical clue formulations

• Unruffled — 2022-11-29
• Unlikely to crack — 2002-04-05
• Composed — 1998-01-02
• ...vegetable... — 1996-12-16
• Imperturbable — 1996-02-28
• Really calm — 1994-12-14
• Completely unperturbed — 1993-12-28