[344] Basil. in Psal. 80.
There are three things considerable in New Moons.[345] First, σύνοδος, the conjunction of the Moon with the Sun. Secondly, ἐξαυγασμὸς, the waxing of the Moon. Thirdly, σχῆμα μηνοειδὲς, the prime of the Moon. In the first it was quite dark; in the second it did open it self to receive the Sun-beams: In the last it did appear, corniculata, horned.
[345] Scalig. de emend. temp. pag. 26. It. p. 105.
Because in all these three degrees of the change, there was a kind of mutual participation both of the Old and New Moon: Hence the Jews observe two daies,[346] namely, the last of every moneth, and the first day of the next following. Now because the thirtieth was the last in their longest months; Hence Horace calleth these last days, Tricesima Sabbata: The first days they termed, Neomenias, new Moons.
[346] Hospin. de Orig. fest. c. 4. p. 15. Eadem ratio tenet etiam in illis mensibus qui constant 29. diebus.
For certain reasons the Jews used a kind of change, or translation of daies; which translation, though it were of use in other months also, yet the greatest care was had in translating the beginning of their year, or their first day in their month Tisri; and he that shall diligently calculate these changes, shall find, that all other translations depended on this first.
Translation of daies was threefold.[347] First, Lunary: Secondly, Politik: Thirdly, Mixt.
[347] Scalig. de emend. temp. l. 2. p. 85.
The reason of Lunary translation, was, that they might not observe the Feast of the New Moon, until the old were quite over-past. For the understanding of this, note these three rules.
First, The Hebrews counted their Holy-daies from night to night, beginning at six of the clock; so that from six of the clock the first night, till the next noon, were just eighteen hours.