Historical clue formulations

• After-school activity? — 2014-01-01
• French island WSW of Mauritius — 2011-08-21
• Celebration that may involve the people in 20-, 42- and 56-Across — 2007-01-16
• What a class might have — 2001-05-08
• Reason to go back to school — 1998-07-19