Historical clue formulations

• Join a conference call, say — 2021-05-30
• Join a conference call, say — 2020-08-31
• Try to reach headquarters, say — 2012-09-16
• Phone headquarters — 2010-09-04
• Try to reach a talk show, say — 2007-12-12
• Join a teleconference — 2005-07-05
• Call a radio show, e.g. — 2004-11-11
• Try to reach a talk show, say — 1998-12-12
• Connect via phone — 1998-09-29
• Phone headquarters — 1994-11-16