Thanks! Makes sense to check within the big names regarding the Mist of Times first. First search hit for Sirius in that book reveals already something quite interesting as it looks like referring to the midnight culmination:

Palamedes was the first to layout the watches of the night, during the Trojan War. And Euripides bears witness, in the "Iphigenia in Aulis", that in
that period they were already accustomed to mark off the sections of the night by astronomical signs:
'What star is this that passes over?
Sirius, near the seven-pathed Pleiades,
still streaking through the midst of the heavens.'
And our Manilius clearly alluded to this passage. [125]
p.208

125: Scaliger, Commentarius, pp. 38-9 ad 1.506: [...] The Euripides passage was a favourite of Scaliger's; he had cited it also in the Coniectanea to VII. 73 and in the Festus commentary (Ch. V, above, n. 77).