My book Put-Out The Light follows the timeline from 607 BC (siege of Jerusalem began), 605 it fell, 537 Cyrus decree (70-years up), 70-years doubled ended with Artaxerxes decree being implemented when Ezra and company literally cleansed the temple 2300-days into Artaxerxes' reign, and from the Day of atonement 457 BC the 2300-years ended twice 1843 and 1844.

Don't forget to have two ending dates for the 2300-year prophecy 1843 and 1844. (The first ending [2300-457=1843], the tarrying time, & the "last ending of indignation" [2300-457=1844])

And there is the 83-years 4-months for the HOUR of His Judgment of the dead (22 October 1844 thru 22 February 1928) that correlates with the dead papacy (1798 thru 1928).

And the 83-years 4-months for the Hour of His Judgment for the living (Yom Kippur - 14 October 1929 thru 14 February 2013) that correlates with the living papacy that was restored in 1929 by Mussolini and ended with Benedict XVI.

I have not followed this thread from the beginning, but I im intrigued by the title.

Biblical calendar? It was E Thiele who demonstrated a rule in the Biblical calender which counted fractions of a year or any time period as a whole unit. To illustrate he would say that if a certain king would become a ruler on December 31, and then die on the following day, January 1, then the record would state that he had ruled for 2 years - even though it was only a very small part of two years.

You need to consider this rule in order to make the Biblical chronology fit into history. Using this rule he solved the problems in the chronology of the Hebrew kings.

Da 6:7 All the presidents of the kingdom, the governors, and the princes, the counsellors, and the captains, have consulted together to establish a royal statute, and to make a firm decree, that whosoever shall ask a petition of any God or man for thirty days, save of thee, O king, he shall be cast into the den of lions.

Da 6:12 Then they came near, and spake before the king concerning the king's decree; Hast thou not signed a decree, that every man that shall ask a petition of any God or man within thirty days, save of thee, O king, shall be cast into the den of lions? The king answered and said, The thing is true, according to the law of the Medes and Persians, which altereth not.

Some have said the year length had changed at the flood, which is about the only conceivable time it could be affected. But what about this, about 600 years before Christ, or a little less than 2000 years after the flood? Why did they say, "thirty days", 10 times three? Why not 28, or one month? Could it be an idea kept from before the flood? Could it be how they numbered the months?

It still appears to be an accounting type of thing to me.

After reading your post I did a search for other passages. Here are two more:

As you've asked, why not a month instead of 30 days. The evidence from the flood account and other ancient texts is that the ancient, biblical calendar tracks both the lunar months that alternate between 29 and 30 days and solar months of 30 days. (In the ancient texts a solar year had 30 day months plus 4 intercalated days per year or 364 days per solar year which was adjusted periodically to align with the seasons.) You can't read too much into these isolated passages but they shouldn't be overlooked. Thirty days on the solar side of the biblical calendar is a solar month.

Are we children of faith? Was Oct 22nd 1844 a lie?

Did the outpouring of the Holy Spirit to proclaim the three angels messages not prepare them to proclaim the message before that date? Did God let men bumble-stumble into the truth and it did not happen when God's messenger said it did?

You all act as if the movement was built off of fantasy instead of prophetic "rocks would cry out if they didn't do it" fulfillment of prophecy. The opening of the sealed book of Daniel happened during that time, the outpouring of the Spirit of Prophecy was received, but this is not enough evidence for you?

If we argue over the point of the Holy Spirit leading the God filled Adventist pioneers to the Karaite calendar, then we deny the fulfillment of the the Spirit of Prophecy. Do you get it? How shameful!

"When April 21, 1844, passed—the time first thought to be the end of the 2300 days—and Jesus did not come, the believers checked and rechecked the basis of their reckoning. Ellen White explained this: {1BIO 49.2} (but we know better now eh?)

"Calculation of the time was so simple and plain that even the children could understand it. From the date of the decree of the king of Persia, found in Ezra 7, which was given in 457 before Christ, the 2300 years of Daniel 8:14 must terminate with 1843. Accordingly we looked to the end of this year for the coming of the Lord. We were sadly disappointed when the year entirely passed away and the Saviour had not come. {1BIO 49.3}
It was not at first perceived that if the decree did not go forth at the beginning of the year 457 B.C., the 2300 years would not be completed at the close of 1843. But it was ascertained that the decree was given near the close of the year 457 B.C., and therefore the prophetic period must reach to the fall of the year 1844. Therefore the vision of time did not tarry, though it had seemed to do so. We learned to rest upon the language of the prophet, “For the vision is yet for an appointed time, but at the end it shall speak, and not lie: though it tarry, wait for it; because it will surely come, it will not tarry.”—Life Sketches of James White and Ellen G. White (1880), 185, 186. {1BIO 49.4}

I hate to say this Brothers, but if you argue with this fundamental point, which takes as much faith to believe as does the eternal Sabbath remaining on the Day of the week that God created it, then where else do you find fault in the foundation of our faith?

Do you think through the passing of time that our brethren are more proficient at determining truth? We are nothing in faith compared to those Pioneers. In fact if we were there, the majority of these brothers would have fallen away after the disappointment!

The prophecy was fulfilled EXACTLY when she was shown it was. If you do not believe this, then you think you know more than the God who gave us this sacred calendar.

I had thought a lunar month was 28.something days?

So, if a month was said to be 30 days when it wasn't, was that left over from before the flood, or had it always been that way? That is, regarding those in Abraham and Daniel's day.

A lunar month is a little more than 29.5 days on average and in my opinion it's always been that way - pre and post flood. (I used to think that the calendar was affected by the flood but according to physics a precise 360 day year of twelve 30 day lunar months is not possible because of the nature of the interactions between three gravitational bodies.) Slightly more than half of the lunar months have 30 days. Have a look at earlier posts regarding solar months in the Bible - always 30 days but usually not aligned with lunar months.

The most enlightening part of this study that I found brother Mark, is the fact that the children of God didn't have a "common" calendar until they fell to Babylon. Then they were forced to comply with Babylonian ideology, and everything started to be less defined in truth in the minds of the captured after that day.

After starting this topic 11 years ago I just came across a fascinating statement in the appendix of the 1888 GC, page 681.4:

Apparently by 1888 the consensus of the church and Ellen White was that the ancient correct reckoning of the Biblical New Year and therefore the timing of the Day of Atonement in 1844 was based on the first new moon after the vernal equinox not the first new moon of the barley harvest as taught by the Karaites.

Why is that important? Because in 1844 the Jews observed Yom Kippur, the Day of Atonement one month too early on September 23. Since their dispersion the Jews no longer calculate their New Year by the vernal equinox rule of scripture. For us today who are waiting and watching for the fulfillment of the ancient feasts that are still unfulfilled - trumpets, tabernacles, and the modified feasts of Ezekiel's temple which are a window into future events at the restoration of the twelve tribes of spiritual Israel, it is important to understand the calendar of scripture.

?? The Catholic Church set's their easter celebration after the equinox calendar, but what I seem to recall what I've read on the Jews... The majority of them their calendar is based on calculation. And they(well most of the Jews) have been using this system since their Babylonian captivity release(690?BC), not only since 70 AD.

However, the Bible teach to determine the start of the calendar via the ripeness of the barley, not the equinox. So I don't know how you can come to conclude with such assurance that the Karaites, who uses the barley ripeness method, that their fall Feast dates was a month too early as oppose to the Adventist having it right?