Historical clue formulations

• Impulsive, as a decision — 2026-03-21
• Leave just after the first person? (Boomer) — 2025-10-26
• Instant … hinted at four times in this puzzle's circled letters — 2022-06-21
• Instant — 2015-08-02
• W — 2015-07-02
• Instant — 2014-10-20
• Blink of an eye — 2012-09-06
• 114-Down near Boise? — 2012-02-05
• Kind of timing — 1998-03-09