Historical clue formulations

• NBC Nightly News anchor before Brian Williams — 2020-03-26
• NBC anchor before Williams — 2014-08-13
• "Today" show host before Gumbel — 2013-07-04
• Tom who wrote "The Greatest Generation" — 2008-08-05
• "The Greatest Generation" author — 2007-05-24
• Evening news anchor — 1996-01-25
• Rather rival — 1994-12-22