Historical clue formulations

• Hole that's not filled — 2009-08-01
• When a team doesn't play — 2003-05-04
• When no games are scheduled — 2002-07-01
• Part of a flexible schedule — 2002-02-02
• Time for a makeup game — 1999-09-01
• It's still free — 1997-09-20
• Break in a baseball schedule — 1995-09-17
• Scheduling break — 1994-06-08