Historical clue formulations

• Solar revolutions — 2026-03-26
• Trips around the sun — 2025-12-07
• Quite a while — 2025-07-13
• 1917, 1984, 2001 and others — 2025-06-24
• They're sometimes in Roman numerals — 2023-07-16
• Junior and senior — 2021-07-27
• Junior and senior — 2021-03-10
• What tree rings represent — 2020-03-23
• Data for auto aficionados — 2019-04-28
• All these ___ ... — 2018-08-11
• What birthday cake candles represent — 2018-04-24
• Freshman, sophomore, etc. — 2018-04-09
• See 49-Across — 2016-07-14
• See 64-Across — 2015-12-30
• Sentence units — 2014-11-01
• See 66-Across — 2013-02-05
• 1492, 1776, 2001, etc. — 2010-10-25
• Senior, junior and sophomore — 2010-09-27
• College classes — 2009-11-22
• Sentence units — 2009-06-02
• A long time — 2005-12-07
• A long time — 2004-12-26
• 2001 and 2010 — 2003-05-20
• Quite a while — 2002-07-14
• Long time — 2002-05-09
• A dog's age — 2001-09-13
• Sentence units — 2001-01-06
• Orbital periods — 2000-03-01
• Millennium makeup — 1998-07-26
• Freshman, sophomore, etc. — 1997-10-28
• Sophomore and junior, e.g. — 1997-07-21
• Vineyard data — 1996-03-10
• Calendar periods — 1996-01-08
• Graduating classes — 1996-01-03
• Long time — 1995-12-06
• Long time — 1994-09-21
• Oh, so many moons — 1993-11-23