June 6 . . . ἀρκτοῦρος2 δύνει.
June 25 . . τροπαὶ θεριναί.
July 19 . . ὁ κύων εῶ̔οσ2 ἐπιτέλλει.
September 17 ἀρκτοῦρος2 ἐπιτέλλει (heliacal rising).
September 25 ἰσημερία φθινοπωρινή.
November 6 αἱ πληιάδες ἑῶ̔αι δύνουσι (cosmic
December 23 τροπαὶ χειμεριναί.
February 25 ἀρκτοῦρος2 ἑσπέριοσ2 ἐπιτέλλει καὶ
(26) χελιδόνες2 πέτονται καὶ φαίνονται.
Spring began with the equinox, but was often
popularly dated from the appearance of swallows
and the acronychal rising of Arcturus in February.
The heliacal rising of the Pleiades marked the
beginning of summer, which ended with that of
Arcturus, an event nearly coinciding with the
autumnal equinox. Finally, winter began with the
cosmic setting of the Pleiades.
A star is said to rise heliacally when it gets far
enough in front of the sun to be visible before
dawn. It sets cosmically when it gets so much
further in advance as to be first seen setting in the
west before dawn. The acronychal is the evening
rising of a star, when it is visible all night, and
contrasts with the heliacal, or morning, rising, when
it soon disappears in the sun's rays.
Galen, in his commentary on the third section of
Aphorisms, implies that there are two meanings of
μεταβολαὶ τῶν ὡρέων, a common term in Airs Waters
(1) the actual changes from season to season ;