Historical clue formulations

• First capital of Japan — 2010-07-23
• Former Japanese capital — 2010-02-28
• Japan's first capital — 2009-06-14
• Japan's first capital — 2005-07-24
• Former Japanese capital — 2000-04-30
• Japan's first capital — 1997-11-14
• Japan's first capital — 1995-12-24