C.E. Graves, Commentary on Thucydides: Book 5

ἄρχει—cf. iv. 118, 8, ἄρχειν δὲ τήνδε τὴν ἡμέσαι, ‘this day to begin it’. In giving the date the year is here put first and forms the subject of ἄρχει, ἔφορος Πλειστόλας being ‘the year of Pleistolas' office’. Then comes the month, and then the day. Comparing the passage cited from Book iv. we find the same variation of two days at Athens and Sparta, while here Elaphebolion corresponds to Artemisins instead of to Gerastius (see note on iv. 119, 1).

ἐκ Διονυσίων εὐθύς—‘immediately after’; i. 120, 3, ἐκ πολέμου πάλιν ξυμβῆναι. The City or great Dionysia were held about the end of March.

καὶ παρενεγκουσῶν—‘with a variation of a few days’. καί here has probably the corrective force noticed on iv. 35, 3, and is equivalent to ‘in fact’, ‘that is to say’. The time that the war lasted was a few days more than ten years, reckoning from the attack on Plataea (ii. 2 sq.); and somewhat less than ten years, counting from the time when the Spartans first took the field with the intention of invading Attica (Arnold). For παρενεγκών, in the sense of varying, cf. ch. 26, 21. A few instances of the same usage are cited from late Greek writers.

ἤ—dependent on the sense implied in διελθόντων, as if ὕστερον had been written.

κατὰ τοὺς χρόνους—i.e. the half-yearly periods by which the writer reckons, as explained below, line 12. See also ch. 26, 20.

καὶ μή—‘and not in accordance with the enumeration of the names of those who, in each several state, either were archons or from holding some office served as a mark for past events’, i.e. whose names were used to date by. Thus in Sparta the years were marked by the names of the Ephors, in Argos by the year of office of the priestess of Hera. The order of this sentence is very awkward, the words τὴν ἀπαρίθμησιν τῶν ὀνομάτων, which depend on κατά, being apparently postponed in order to give the most important words an antithetical prominence. But probably τὴν ἀπαρίθμησιν τῶν ὀνομάτων ought to be transposed and placed either immediately after μή, or at the end of the sentence after σημαινόντων. Corresponding to ἢ ἀρχόντων we have ἢ ἀπὸ τιμῆς τινὸς σημαινόντων. σημαίνειν ἐς is ‘to furnish a mark as regards’; cf. ii. 8, 3, ἐδόκει ἐπὶ τοῖς μέλλουσι γενήσεσθαι σημῆναι=σημεῖον εἶναι: so σημαίνει stands absolutely in ii. 43, 3. Classen however suggests that ἐς should here be omitted. πιστεύσας μᾶλλον is added for the sake of emphasis, without affecting the construction.

ἀκριβές—in its strict sense, implying exactness of detail. οἷς καὶ κ.τ.λ.—an indirect construction, dependent on ἀκριβές. ‘For whether an event occurred in the beginning, or the middle, or whatever might be the exact point, of a magistrate's term of office is left uncertain by such a mode of reckoning’ (Jowett). Classen however takes the clause οὐ γὰρ ἀκριβές as parenthetical ‘this gives no exactness’: and makes οἷς=ὅτι τούτοις. καί here has a disjunctive force, as noted on ch. 15, 6.

ἐξ ἡμισείας—‘as each (of these periods) has the value of the year in half-measure’, i.e. is equivalent to half a year. With ἡμίσεια ‘half’, μοῖρα is probably understood: cf. Dem. Fals. leg. 431, ἐφ̓ ἡμισείᾳ χρηστὸν εἶναι. In such phrases as ch. 31, 9, the gender is determined by the following noun, and so here it might be referred to δύναμιν.