Historical clue formulations

• What to call it when it's over — 2019-04-30
• Hangs it up — 2015-09-04
• What you might call it — 2015-08-01
• Calls it a day — 2015-05-27
• What a resignee calls it — 2007-04-06
• Cuts out — 2006-09-02
• Throws in the towel — 2006-05-02
• What you may call it? — 2001-10-25
• Call it _____ — 1993-12-18