Historical clue formulations

• "___ Green" (Kermit the Frog song) — 2026-06-19
• Hippie happening — 2025-12-06
• Hippie confab — 2021-09-04
• Hippie celebration — 2012-12-27
• 1960s hippie event — 2011-10-19
• Summer of Love prelude — 2011-04-30
• Hippie happening — 2009-03-27
• "___ Green" (Kermit the Frog song) — 2008-02-04
• "It's not easy ___ green" — 2007-01-01
• 60's protest — 2005-05-26
• 60's happening — 2005-05-18
• Peaceful gathering, 60's-style — 2005-01-08
• "Hair" tune — 2004-05-08
• Hippie gathering of a sort — 2002-06-16
• Hippie gathering of a sort — 2000-10-29
• 60's event — 1999-01-10