Generally, a relative clause starts with a relative pronoun and it may be a defining clause or non-defining clause. These clauses are also called adjectival clauses. There is another relative clause which is known as an adverb relative clause, it may also be a defining or non-defining clause. It also defines a noun related to time,place and reason.
1.I can't remember a time when I was so happy.
What terms do we use for these adverb relative clause? ( We generally use the term adjective clause for the relative clause containing relative pronoun)
Could you please explain it?