Does ὅταν with subjunctive mean not sure action (Rev. 11:7)

Question

In Rev. 11:7 ὅταν is used with subjunctive tense.

Does it mean that we can't conclude from this verse that Rev. 11:7 does not state that two witnesses will necessarily finish witnessing and will necessarily go in the cloud to heaven?

Answer 1

It's expressing the temporal nature of ὁταν (whenever). The uncertainty is with time; not with the completion of the action.

The subjunctive is frequently used after a temporal adverb (or improper preposition) meaning until (e.g., ἕως, ἄχρι, μέχρι), or after the temporal conjunction ὅταν with the meaning, whenever. It indicates a future contingency from the perspective of the time of the main verb. -- Wallace, D. B. (1996). Greek Grammar beyond the Basics: An Exegetical Syntax of the New Testament (p. 479). Grand Rapids, MI: Zondervan.

When they shall have finished (ὁταν τελεσωσιν [hotan telesōsin]). Merely the first aorist active subjunctive of τελεω [teleō] with ὁταν [hotan] in an indefinite temporal clause with no futurum exactum (future perfect), “whenever they finish.” -- Robertson, A. T. (1933). Word Pictures in the New Testament (Re 11:7). Nashville, TN: Broadman Press.