Historical clue formulations

• Apt rhyme of "clock" — 2026-08-05
• Half time? — 2025-12-19
• Tick follower — 2022-06-26
• Tick-___ — 2020-09-14
• Half-a-second sound — 2015-06-27
• Clock sound — 2013-10-23
• Clock sound — 2012-03-04
• Tick-___ — 2009-05-04
• Clock sound — 2007-12-01
• Clock sound — 2006-02-21
• Clock sound — 2002-01-28
• It's heard around the clock — 1999-01-30
• Clock sound — 1997-07-20