Historical clue formulations

• Bikini, e.g. — 2021-08-13
• 60-Down, literally? — 2017-08-27
• Bikini, notably — 2017-04-08
• Where to take an exam — 2009-06-04
• Bikini atoll, once — 2004-02-10
• Bikini, once — 2002-06-28