As others in this conversation have observed, there is a big difference
between these two:

  The exam is Thursday.
  The exam is a take-home.

Clearly the noun phrase in the second ("a take-home") is what has
traditionally been called a subject complement or predicate nominative.
"Thursday" in the first, however, is an adverbial and has a quite different
role.  That isn't in dispute.  Whether we want to call it a "complement" is
a matter of classification and comes down to how we choose to define
"complement."

There is certainly a difference between the adverbials in these two sentences:

  The game was yesterday.
  The boys were heroes yesterday.

In the second of this pair, "yesterday" is a classic time adverbial that
modifies the predicate.  In the former, the adverbial "yesterday" completes
the predicate and so, as Michael Kirchner suggests, could reasonably be
classified as a complement.  In the following sentence:

  The family was here yesterday

we could then call "here" a complement (predicate adverbial?) but not
"yesterday," which is a standard adverbial.

Dick Veit

>Date: Wed, 10 Mar 1999 09:28:31 -0800
>From: Michael Kischner <[log in to unmask]>
>Subject: Re: Adverbs of time/place as complements
>
>I never suggested that adverbials such as "Thursday" in "The exam is
>THursday" could be considered a noun subject complement.  Agreeing that it
>is certainly an adverbial, I merely ask whether it could be considered a
>_complement_ -- one as yet unnamed in most traditional grammars.  That is,
>isn't "THursday" a completer rather than a modifiers of "is"?
>