Historical clue formulations

• Prepares to get schooled, perhaps — 2022-05-17
• Signs up — 2021-09-09
• Joins — 2012-02-04
• Joins up — 2008-03-09
• Matriculates — 2002-12-25
• Records — 2002-06-22
• Signs up — 2001-04-03
• Signs up — 1998-02-09
• Recruits — 1994-11-20
• Registers — 1993-12-12