Historical clue formulations

• -s or -ed — 2020-09-13
• Part of a movie that can be spoiled — 2019-01-16
• It may be spoiled — 2017-09-15
• You may get annoyed if it's given away — 2009-10-03
• Part of a whodunit that reveals who done it — 2009-08-03
• Place for an O. Henry surprise — 2002-12-18
• Bad thing to give away — 2001-03-24
• O. Henry surprise — 1999-08-08
• Novelist's need — 1999-06-27
• Windup — 1995-12-29
• Denouement — 1995-04-23