O tempora, o mores!
How can this be true when the people of God abhor and do not admit pagan calendar and dates in their feasts? I've never encountered ''December'' or the birthdate of anyone in the Holy Scriptures.
I've found that the Biblical and astronomical years, months, days and hours without Rabbinic and Popish delusions and stumbling blocks are such.
1. The day begins before sunrise in the morning and ends after sunrise in the evening. This first meaning of the day is slightly longer than the twelve hours in the day, because it includes the light of the morning and the evening - Genesis 1:4-5 (NIV and YLT translate the first chapter of Genesis more literally and correctly unlike most other translations), John 11:9.
2. Night begins whenever two or more stars become visible to the naked eye and ends whenever one of the last two stars become invisible to the naked eye. This is slightly shorter than the twelve hours in the night. This accommodates for the morning and evening star and the plural stars, and provides a demarcating sign between day and night - Genesis 1:18, Psalm 136:9.
3. The second broader meaning of a day includes the portion of the night that follows. This does not apply to the seventh day of the week - Gen. 1:5, Gen. 1:8, Gen. 1:13, Gen. 1:19, Gen. 1:23, Gen. 1:31, Gen. 2, Lev. 22:30.
4. The first day of the week includes the night portion after the seventh day since the evening follows the light in that day - Gen. 1:1-5, Gen. 2:1-3, Matthew 28:1.
5. The first day of the month begins with the first morning after conjunction from Zion. It is a hidden Moon - Numbers 10:10, Numbers 28:11, 1 Samuel 20:5, 1 Samuel 20:18, Psalm 81:3.
6. The first month of the year begins when the morning of the fifteenth day of the same month falls after the vernal equinox and the morning of the fifteenth day of the seventh month falls after the autumnal equinox. If one criteria isn't met, there is a thirteenth month - Exodus 12:2, Deuteronomy 16:1, Exodus 23:16, Exodus 34:22.
7. Only the first day of the unleavened bread and the day of atonement are said to be sabbaths from the evening of the previous day to the evening of the next. The seventh day sabbath and the other five high sabbaths begin from morning and last until evening unless the seventh day sabbath happens to coincide with the aforementioned two high sabbaths - Lev. 23:5, Lev. 23:32.
Our Lord was crucified between the two evenings (for there are different meanings of ''evening'' in the Torah) on the fourth day, which was before such high sabbath and raised on the sixth day of the week before sunrise as a firstfruit in accordance with the Scriptures and to fulfill his prophecy of being 3 days and 3 nights in the heart of the earth - Matthew 12:40.