Estimating Jesus’ Birth
by Chas D. Mayfield
To understand when Jesus was born, we have to go back about 18 months to the beginning of the Jewish New Year. Add up the weeks
- 2 (for the Passover and Pentecost weeks) +
- 8 (Zachariah served the 8th division of Abijah) +
- 1 (Luke 1:23 Elizabeth conceived immediately?) +
- 40 (gestation of John) +
- 27 (6 final months of Jesus' gestation) =
78 weeks later or early October.
One of the difficulties of breaking this down is that we are dealing with the Jewish calendar (starts on the spring new moon) and the Gregorian calendar (starts January 1 since Julius Caesar's time). The Jewish calendar year is measured by lunar cycles which makes the Jewish year of 12 lunar months to be 11 days shorter than the 365-day year measured by a circle of the sun on our modern calendar. The Jewish year of 12 lunar months is a week and a half or 11 days (unless it's the leap year with an added month which happens every few years when it's still too cold to plant) shorter than the modern calendar. So the 78 weeks on my chart is about 2 weeks shorter than the "18 months" on the chart. 18 months is general and intended to give a snapshot that we are talking about the season of the year that's the opposite season of springtime and Passover.
The Jewish Passover "holiday" called Pesach is in 2017 was dated April 11-18. The Passover starts 2 weeks after the new moon (see chart that the spring new moon is at the end of March). Though the Jews went by a lunar calendar, the week was still a week and hence the same number of days regardless of the calendar being used. So we are definitely looking at a starting point of the beginning of April thereabout (since the new moon for spring varies from year to year). Therefore the weeks are pretty much fixed (if Elizabeth conceived quickly after Zachariah finished his service in the temple). So count those weeks from the beginning of April, the 78 I have counted up, and it's the end of September. It is just an estimate.
The chart is a little difficult to follow. Suffice it to say that if John the Baptist was conceived immediately after the promise made by the angel, their age and the "fullness of the times" in Galatians 4:4 suggest immediacy to me, then there are only about 18 months to deal with. That 18 months begins 2 weeks before the New Year and New Moon of Spring. That puts you in the fall, not the Spring, for the birth of Jesus. For Jesus to be born in the Spring, you have to come up with another 6 months. That is my final explanation.
One person asked me: Does it matter? My answer is, sure, it matters. In the course of studying about Jesus's birth, it is asked if the date was December 25. How do you know? The question begins the investigation so that things like new possible dates come up. I'm not fighting with anyone over it. It's just a good discussion. I don't believe it's merely academic. Knowing more about Jesus should be rewarding as it adds to what is true and what is not.
