Historical clue formulations

• Old-style warning — 2017-07-16
• Old-style call to arms — 2008-04-26
• Warning signal, once — 2007-09-02
• "When the angry trumpet sounds ___": Shak. — 2005-02-04
• Old-fashioned warning — 2005-01-01
• Warning sound, once — 2001-10-27
• Old-fashioned warning — 2000-12-09