Temporal clauses are introduced by conjunctions or relative expressions having the force of conjunctions
A. Denoting time usually the same as that of the principal verb:
ὅτε, ὁπότε, ἡνίκα, ὁπηνίκα
N. 1.—ἕως means
N. 2.—ἡνίκα, ὁπηνίκα have the force of what time, at the moment when, when, (rarely
N. 3.—Poetic or Ionic are εὖτε (= ὅτε)
N. 4.—ἔστε is used (rarely) in lyric, Sophocles, Euripides, Herodotus, Xenophon.
B. Denoting time usually prior to that of the principal verb:
C. Denoting time subsequent to that of the principal verb:
ἕως, ἔστε, μέχρι, μέχρι οὗ (rarely ἄχρι), ἄχρι οὗ
πρίν, πρότερον ἤ
N.—Homer has also ὄφρα (also final), εἰς ὅτε (κε), εἰς ὅ (κε). Herodotus has ἐς ὅ, ἕως οὗ, ἐς οὗ
Demonstrative adverbs in the principal clause often correspond to the relative conjunctions, as ὅτε . . . τότε, ἐν ᾧ . . . ἐντούτῳ, ἕως . . . τέως (μέχρι τούτου). So also ἐπεὶ . . . τότε, ὡς (ὅτε) . . . ἐνταῦθα, etc.2385
Some temporal conjunctions also denote
ὅτε, ὁπότε, ἐπεί, εὖτε (poet.), ἐπειδή
A temporal sentence and a conditional sentence may occur in close conjunction without marked difference of signification.
ὅταν δὲ νοσήσωσιν, ὑγιεῖς γενόμενοι σῴζονται· ἐά_ν τέ τις ἄλλη συμφορὰ_ καταλαμβάνῃ αὐτούς, τὰ ἐναντία ἐπιγιγνόμενα ὀνίνησιν
A temporal conjunction is often used in Greek where English employs a conditional or a concessive conjunction.
οὐκ ἂν ἔγωγε Κρονί_ονος ἆσσον ἱκοίμην, . . . ὅτε μὴ αὐτός γε κελεύοι
The time denoted by a temporal clause is not always solely contemporaneous, antecedent, or subsequent to that of the principal clause, but may overlap with the time of the principal clause (before and at the same time, at the same time and after, until and after).
ἐπεὶ δὲ ἠσθένει Δα_ρεῖος καὶ ὑπώπτευε τελευτὴν τοῦ βίου, ἐβούλετο τὼ παῖδε παρεῖναι
ὁ δ' ἔν τε τῷ παρόντι πρὸς τὰ μηνύ_ματα ἀπελογεῖτο καὶ ἑτοῖμος ἦν πρὶν ἐκπλεῖν κρί_νεσθαι
a. Conjunctions of antecedent action usually take the aorist, rarely the imperfect except when that tense represents overlapping action, as in
b. A verb of aoristic action is used: in the temporal clause when complete priority, in the main clause when complete subsequence, is to be clearly marked.2389
Clauses introduced by relative adverbs (or conjunctions) of time, have, in general, the same constructions as clauses introduced by relative pronouns ( cross340, cross2493 ff.) and by relative adverbs of place and manner. Temporal clauses are treated separately for the sake of clearness.
a. Temporal clauses introduced by a word meaning
b. Strictly ὅτε, ἔνθα, ὡς, etc., are subordinating conjunctions when the clause introduced by them fixes the time, place, or manner of the main clause; but are relative adverbs when they serve only to define the antecedent and introduce a clause merely supplementary to the main clause.2390
Temporal clauses are either definite or indefinite.2391
A temporal clause is definite when the action occurs at a definite point of time (negative οὐ, except when the special construction requires μή). Definite temporal clauses usually refer to the present or to the past.2392
A temporal clause is indefinite when the action (1) occurs in the indefinite future, (2) recurs an indefinite number of times, (3) continues for an indefinite period. The same clause may have more than one of these meanings. (3) is rare. The negative is μή. Indefinite temporal clauses refer either to the future or to general present or past time.2393
The same temporal conjunction may refer either to definite or to indefinite time; sometimes with a difference of meaning.2394
When the time is definite, the indicative is used; when indefinite, the subjunctive with ἄν, the optative, or (rarely) the indicative.
Temporal conjunctions with the subjunctive take ἄν. (For exceptions, see cross2402, cross2412, 2444 b.) ἄν is not used with the optative except when the optative is potential, 2406, 2421 (cp. cross2452).
Herbert Weir Smyth [n.d.], A Greek Grammar for Colleges; Machine readable text [info] [word count] [Smyth].