Historical clue formulations

• Heyday of many serials — 2018-11-17
• When soap operas first flourished — 2017-02-05
• Golden age for voice acting — 2015-04-25
• Late 1920s to around 1950 — 2009-08-16
• Time before TV — 2009-08-14
• The 30's and 40's, e.g. — 1998-01-01