Historical clue formulations

• On ___ (how some pranks are done) — 2014-07-15
• On ___ (when challenged) — 2007-09-03
• On ___ (how pranks may be done) — 2005-08-30
• How a prank may be done, after "on" — 2003-07-29
• Venturing, after "on" — 1995-05-26
• Antarctic cape — 1994-01-22