[Casiopea]

Originally Posted by ian2

I am not sure we should call the following a relative clause:

It started to snow when I left work

Your observation is correct. It's not a Relative Clause (RC) in the strict sense of the term (i.e., an attributive clause). It's an adverbial clause that is relative to the time of the event, which makes it a relative, adverbial clause.


Here's a definition that might help:

an attributive clause is a subordinate clause that functions as an attribute of a noun phrase. Attributive clauses refer to and qualify a noun (or a pronoun) in the main clause.

Attributive clauses that are introduced by an introductory word are called relative clauses.

Introductory words: relative pronouns, relative adverbs, and participles in reduced relative clauses.

Source (German site)

Does that help so far?