Historical clue formulations

• Tried out — 2025-02-15
• Tried-and-true — 2022-04-16
• Checked out — 2022-03-10
• Like students at semester's end — 2021-02-09
• Put into beta — 2019-03-30
• Gave an exam — 2017-05-16
• Proven — 2015-03-15
• Worked on in the lab — 2010-11-14
• Took for a trial run — 2010-01-25
• Tried out — 2007-04-02
• Tried out — 2005-11-15
• Checked out — 2004-10-08
• Known to be in working order — 2001-05-26
• Tried and true — 2000-03-27
• Time-___ — 1999-09-05
• No longer green — 1998-12-13
• Taken around the track — 1998-03-04
• Like a Car and Driver car — 1997-06-15
• Checked — 1996-06-05
• Proven sound — 1995-01-26
• Tried by fire — 1994-08-06