I see. Most of the source books and reports are scholarly and don’t seem to be freely available on the internet. Still, here are some sources from the internet. It’s a lot to take in:
First, this is a good overview (the link first listed below)
One little conceptual mistake (common among the following links) is this author lets creep in is references to ancient ‘weeks’. But the the ancient Israelites of the bible had no concept of weeks. They had days, months, and years. They had Sabbaths and days in-between. They had “hours” where each day consisted of 12 hours from dawn to dusk, which then varied in length as the seasonal length of the days changed. But “weeks” to them would be a foreign as “minutes” and “seconds”, which they also didn’t have.
The overview is written by, Denis O’Callaghan Ph.D., D.Litt., D.Phil., Th.D., who appears to be a scholarly Adventist. He even quotes Ellen White:
One key item O’Callaghan knows but fails to note is that lunar months are never 28 days long, but instead either 29 or 30, which creates an interesting mathematical conundrum. Read on…
Here are some additional links to more information:
I worked this up to describe what I’ve learned:
Some interesting dates close to today:
1 Kislev will be the next new moon Sabbath on the original Jewish Calendar, which is next Friday: Using the old method, there will then be 4 “Friday” sabbaths in a row.
1 Tevet will start on Sunday Dec 9 then there will be four “Sunday” sabbaths in a row.
1 Shevat will start on Monday Jan 7 and then there will be four “Monday” sabbaths in a row.
You can see why this drove the Romans crazy and they finally ended it.