1866 W. F. Collier iii. 82 The Adverb Clause; as, He will surely come, when he knows that I am here.
1904 C. T. Onions §61a Absolute Clauses..are equivalent in meaning to Adverb Clauses of Time, Reason, Condition, or Concession.
2011 (Nexis) 23 Jan. She asked her students to identify adverb clauses on the small pink slips of paper.