Historical clue formulations

• Change gears — 2026-02-16
• Paradigm movement — 2023-08-17
• Work period — 2022-10-05
• Get into gear — 2020-11-08
• With 61-Across, a possible title for this puzzle — 2009-02-18
• Key over Control — 2007-07-22
• Leave first or second, say — 2005-04-17
• Go from second to third, say — 2003-08-31
• Typewriter key — 2003-01-27
• Tab neighbor — 1999-04-11