Historical clue formulations

• According to experiments, they can't "sleep" in space — 2025-09-19
• Toys that have their ups and downs — 2025-09-01
• Oscillates wildly — 2022-10-01
• Dingbats — 2020-12-22
• Toys on strings — 2020-04-20
• Idiots — 2020-04-01
• Goes back and forth quickly — 2019-02-19
• They can sleep if you play with them — 2016-07-24
• Asses — 2015-04-10
• Toys on strings — 2014-10-27
• Goes on and off diets, say — 2014-06-06
• Jerks — 2013-08-25
• Idiots — 2011-04-03
• Goofballs — 2011-02-26
• Shows great instability — 2010-09-11
• Fluctuates wildly — 2009-07-28
• Dingbats — 2009-04-02
• Fluctuates wildly — 2009-02-22
• Goes up and down — 2008-07-06
• They come with strings attached — 2008-06-28
• Toys that have their ups and downs — 2008-06-18
• Goes up and down — 2005-01-23
• They may give you many happy returns — 2004-05-07
• Goes up and down and ... — 2004-03-09
• Duncan toys — 2002-09-23
• Toys on strings — 2002-04-23
• They can sleep while you watch — 1999-01-03
• They're used in walking the dog — 1998-07-06
• Is wildly unstable — 1998-03-05
• Shows wild instability — 1997-10-26
• Ninnies — 1995-11-05