This has gotten a little off the thread, but maybe I caused that.
The Levite duties were divided in twenty-fourths. If they were divided evenly through twelve months (Ancient Hebrew Calendar), each term was slightly over two weeks.
My studies show that the first month (Nisan) was about the same as our April. Zacharias was appointed to 'the course of Abia', which was the eighth 'course' (1 Chron. 24:10). That would be the last half of our July (Tammuz).
Here's where the dates are harder to pinpoint. How quickly did Elizabeth conceive? I don't think the Lord would have procrastinated the opening her womb, and I doubt Zacharias would have delayed getting together with his wife after his journey home (whatever distance that was). So I'll be helpful to the 12/25 crowd and say Elizabeth conceived in late August (Ab).
Elizabeth hid herself five months. We would be at late Jan. The Angel appears to Mary 'in the sixth month'. Let's be kind once more to the 12/25ers and say that Mary conceived in the last few days of that sixth month, Feb (Shebat).
Nine months later we find ourselves at late Nov (Bul). So now we can see the real meaning of 'Thanksgiving Day'.
I helped the 12/25 folks and still came up a month short.
Personally, I think that the birth was probably earlier than that, maybe as much as a month. Who knows.
That's why I follow the Lord and his apostles lead, and emphasize the kingdom of God and being born again.
seamole, I can't speak for the shepherds in the holy land 2000 yrs ago. I was an active beef producer for over 30yrs, and therefore know a little about animal husbandry. But here's some facts about raising sheep from my sheep producer neighbor.
When all there is available is primitive shelter, shepherds are not going to allow breeding to cause winter lambing. The wet newborns can die from exposure. 40F or below is not good.
Winter lambs and their mothers (ewes) require 3 or 4 times the care of ewes alone. This causes greater stores of resourses such as hay, grain, straw, etc. (which cut into bottom line).
Early spring lambs get to start in a warmer climate, the pasture is cleaner than a cramped stall, and the grass is easier to their little mouths to chew and digest than dried forage.
So I remain skeptical about hebrew shepherds in 1 A.D. lambing in Dec or Jan. Therefore, I believe the Word, that the shepherds were in the fields (probably mid-fall) watching their flocks by night when the angels sang (WOW, just try and picture being there!).
Added thoughts are of course welcome.