The biggest argument against calculation is that the knowledge at the time derived from Hippocrates who declared that pregnancy lasted 8 months.
The biggest argument for the adaptation of a pre-Roman pagan tradition is the existence of the shepherds who watched their flocks by night. This is indeed something shepherds do but the do it in the spring when the ewes are giving birth so they can assist with difficult births, not during the Christmas season.
If Dec. 25th was derived from pagan influence ... then the birth of Jesus associated to Dec. 25th is clearly a reference to the sun 'standing still' during the winter solstice. The winter solstice is when the days starting getting longer ... what is clearly not a coincidence is that Dec. 25th is associated to the birth of Jesus ... the 'sun' of god being reborn. Sol Invictus. Fast forward to the spring equinox which is aligned with Easter and when 'Jesus is crucified' both seem to be associated with the moon and a balance achieved (equinox) the length of the day equals the night.
Btw what is Ostara? The answer is how the spring equinox became Easter.
If as the article suggests the date of death of Jesus was March 25th .... then ask yourself why does the date of Jesus' death move around from one year to the next but his birth on Dec. 25th does not? Is there another factor involved?
Is it because it is somewhat dependent on when the Jewish Passover occurs which is calculated using the cycles of the moon?
Yes. is the simple answer. The Jewish Hebrew calendar is a lunar-solar whereas the Christian Gregorian calendar is solar.
What is interesting about March 25 or 3/25 is that it was the Council of Nicea which convened in 325 AD that dealt with the controversies of when the month of Nissan actually began. The Council had separated the Easter computation from all dependence, positive or negative, on the Jewish calendar.
Hence the life and death of Jesus is clearly entangled with a SUN + MOON narrative which is found in many CULTures around the world from which Christianity obviously borrowed.
BTW Saturnalia was originally celebrated on December 17 before it was extended to three days and eventually to seven days. (hmm both 3 and 7 are considered mystical/magical numbers in Christianity)
First 3 days, then 7 days, now compare to the 12 days of Christmas which last from Dec. 24/25 to Jan. 6/7 marking the Eastern Orthodox celebration Feast of the Epiphany.
Is it a coincidence that 3, 7, 12 in fact are the 22 letters of the Jewish alphabet broken down into 3 mothers, 7 doubles and 12 simple letters?
Saturnalia was a celebration in honor of Saturn. Hence we have two celebrations ... Saturn and the Sun.
Which long ago were the two celestial objects that depicted the boundaries of our solar system using 'naked eye' observations from the Sun out to Saturn.
What was Saturnalia?
Saturnalia, the most popular holiday on the ancient Roman calendar, derived from older farming-related rituals of midwinter and the winter solstice, especially the practice of offering gifts or sacrifices to the gods during the winter sowing season. (Hence the scythe associated with Saturn)
People decorated their homes with wreaths and other greenery, and shed their traditional togas in favor of colorful clothes known as synthesis. Even enslaved people did not have to work during Saturnalia, but were allowed to participate in the festivities; in some cases, they sat at the head of the table while their masters served them.