Historical clue formulations

• Electricians — 2018-02-11
• Linemen — 2011-05-14
• Some building contractors — 2002-11-09
• Cable workers, e.g. — 2002-09-14
• Electricians, at times — 2002-08-19
• They make connections — 1998-07-26
• Electricians — 1995-09-10