Historical clue formulations

• Monkey suits — 2019-11-09
• Ball togs — 2018-06-01
• Prom duds for guys — 2015-05-18
• They're often seen with bows — 2013-09-12
• Fancy duds — 2012-07-04
• They often come with vests — 2011-07-15
• Frequent Astaire wear — 2004-10-05
• Guys' prom attire, informally — 2002-08-20