Historical clue formulations

• Up and back, in a pool — 2022-01-03
• Full circuit — 2017-02-11
• 400 meters, in Olympic track and field — 2013-07-04
• 400 meters, maybe — 2013-04-17
• 440 yards, for many runners — 2010-10-30
• Short swim — 2009-10-18
• Basic pool exercise — 2009-03-05
• Complete circuit — 2005-10-15