ὁπηνίκᾰ · hopēnika — LSJ
at what point of time, at what hour, on what day, at whatever hour, time, whenever, when
at what point of time, at what hour, on what day, more precise than ὁπότε, S. OC 434, Th. 4.125, Theoc. 23.33 ; though sts. it cannot be distd. from ὁπότε, Pl. Alc. 1.105d, Jul. Or. 7.204a, al. ; ὁπότε καὶ ὁ. Pl. Lg. 772d ; ὁ. ἄν at whatever hour or time, S. Ph. 464 ; whenever, PGiss. 53.3 (iv A. D.); simply, when, LXX 4 Ma. 2.16.
2 what time
in indirect questions, in answer to a direct question, πηνίκʼ ἐστὶν ἄρα τῆς ἡμέρας ;— ὁπηνίκα; what time of day is it ?—what time, do you say ? Ar. Av. 1499.
3 what time
c. gen., οὐδεὶς οἶδʼ ὁ. ἐστὶ τοὐνιαυτοῦ what time of year, Id. Fr. 569.7.
II when once
with conditional or causal force, ὁ. ἐφαίνετο ταῦτα πεποιηκώς when once it was seen that . . , D. 18.14, cf. 21.42.