Historical clue formulations

• Billion years, astronomically — 2026-08-25
• Astronomically long time — 2025-08-11
• Long, long time — 2025-01-09
• Seemingly forever — 2024-11-17
• Immeasurably long time — 2024-06-30
• Many millennia — 2024-03-26
• Long span of time — 2023-10-15
• Forever and a day — 2023-10-11
• "___ Flux" (1990s animated sci-fi series) — 2023-01-18
• "___ Flux" (1990s MTV series) — 2022-08-31
• Lo-o-o-ong time — 2022-08-02
• Years and years — 2022-05-08
• "___ Flux" (onetime sci-fi series) — 2021-11-21
• Word derived from the Greek for "age" — 2021-02-20
• Timeline swath — 2020-03-28
• "___ Flux" (2005 film) — 2019-11-30
• Very long time — 2019-08-14
• "___ Flux" (1990s sci-fi series) — 2019-04-17
• Long, long time — 2019-02-19
• More than a millennium — 2018-03-18
• MTV's "___ Flux" — 2017-01-25
• "___ Flux" (Charlize Theron film) — 2016-10-23
• Very long span — 2016-10-01
• "___ Flux" (1990s animated series) — 2016-07-10
• "___ Flux" (Charlize Theron film) — 2016-02-07
• Division of geology — 2015-05-09
• "___ Flux," 2005 sci-fi film — 2014-12-14
• Forever and a day — 2014-10-15
• Unit in a geology book — 2014-05-30
• Many, many moons — 2014-05-27
• Long, long time — 2014-05-21
• Many millennia — 2014-01-28
• "___ Flux" (Charlize Theron movie) — 2013-11-20
• Part of the earth's history — 2013-04-20
• Many ages — 2013-03-31
• ___ Flux (Charlize Theron role) — 2013-02-13
• Ages and ages — 2012-05-13
• Very long time — 2012-01-09
• Very long time — 2011-07-27
• Long, long time — 2011-07-18
• Big stretch? — 2011-06-02
• Time in earth's history — 2010-06-15
• Astronomical unit — 2010-06-12
• Long, long time — 2009-09-16
• Geological range — 2008-10-30
• "___ Flux" (Charlize Theron film) — 2008-04-15
• It goes on and on and on — 2007-09-08
• With 64-Across, 2005 Charlize Theron title role — 2007-06-19
• Long, long time — 2007-05-14
• Interminable time — 2006-11-28