Historical clue formulations

• B-side to the Beatles' "Ticket to Ride" — 2020-08-23
• Firm affirmation — 2019-12-06
• Confirmation declaration — 2012-06-01
• Beatles tune that begins "If you wear red tonight" — 2012-05-05
• "Indeed so" — 2011-11-19
• Insistent affirmation — 2007-04-20
• Answer to "No, that's not!" — 2006-12-16