There are some studies that claim that the timing given in the first several chapters of Ezekiel support the existence of a thirteenth month, which is required for calendars that use the moon to define each month. A summary of the study is as follows: On the fifth day of the fourth month of the fifth year, Ezekiel has a vision, mourns for seven days, lies on one side for 390 days, flips and lies on another side for 40 days, and eventually is sitting in his house with the elders of Judah with him, and it is it the fifth day of the sixth month of the sixth year. Based on the timing of events, at least 437 days expire for Ezekiel. For a solar calendar, there would be approximately 425 days between the given start date and end date; for a lunar calendar with the added thirteenth month in the count, there would be approximately 443 days between the given start date and end date. According to this study, only the lunar system, with its thirteenth month, would satisfy the scriptural account. For the full study, please see http://www.sightedmoon.com/files/Ezekiels 30 days.pdf .
Before I set forth my rebuttal to this study, I would like to quickly summarize why a thirteenth month theory is throughout the rest of scripture not acceptable.
• There is no captain with his 24,000 men army division provided for in a thirteenth month (1 Chronicles 27)
• There is no governor for a thirteenth month (1 Kings 4)
• There is no fruit on the tree of life for a thirteenth month (Revelation 22)
• There is no mention of a thirteenth month by name in scripture, although every other month is mentioned at least two times.
• There is no unique name for a thirteenth month in either the ancient Babylonian calendar, or the Jewish calendar, which derived its month names from the Babylonian calendar.
• The dating of the ancient Babylonian calendar was based on the rising of stars and not the cycle of the moon (see Mul Apin tablets http://www.geocities.com/astrologymulapin/index.htm specifically section four)
• There are not enough days in a lunar calendar system to fulfill Noah's account in Genesis 7-8.
• There are not enough days in a lunar system to achieve 1260 days in 42 months (Revelation 11:2-3)
In Ezekiel chapter 4, Ezekiel is told to take several steps to establish a siege against Jerusalem:
Take a tile & lay it before you, and portray the city, Jerusalem, on it.
Lay siege against it and build a fort against it.
Cast a mount against it.
Set the camp against it.
Set rams against it round about.
Take an iron pan and set it as a wall of iron between you and the city.
Set your face against it, and it shall be besieged, and you shall lay siege against it.
Ezekiel is also told to lie on his left side and lay the iniquity of the house of Israel on it... a day for each year ... 390 days.
Now verse 6 says, "And when you have accomplished them, lie a second time (sheni) on your right side and you shall bear the iniquity of the house of Judah forty days; I have appointed a day for a year." The question at hand is, what is the word, them, referring to? If it is referring to the 390 days, then the 40 days would follow, for a total of 430 days. However, if the 'them' is referring to the siege works, then the 40 days would be within the 390 days.
The first support of the latter, where the 40 days in within the 390 days, is the next two verses: v. 7-8 "Therefore you shall set your face toward the siege of Jerusalem, and your arm uncovered, and you shall prophesy against it. And behold, I will lay bands upon you and you shall not turn from one side to another, till you have ended the days of your siege. Here, the determining factor is not the finishing of 390 days, but the completion of the siege.
A second support of the 40 days being included in the 390 days is in verse 9: "Take also unto you wheat, and barley, and beans, and lentils, and millet and fitches, and put them in one vessel, and make bread thereof to the number of days that you shall lie upon your side, three hundred and ninety days you shall eat thereof." Here, the scripture indicates that the total number of days of lying on a side, and total number of days of eating the bread is 390 days.
All of the days of Ezekiel lying on his side and eating the bread are pictures of the exiles of Israel and Judah. One illustration of this is in verse 13 that says, "And YHWH said, Even so shall the children of Israel eat their defiled bread among the Gentiles where I will drive them." Continuing in chapter 5, Ezekiel is told that once the siege is finished, he is supposed to shave his head and cause some of the hair to be burned, some to be smitten with the knife, and some to be scattered to the wind. All of these things are to show the slaying and scattering of Judah. The end of the scattering is described in Ezekiel 39:26-29.
This leads to a third picture of the forty days being within the 390 years. The final sacking of Jerusalem was approximately 586 BC. There was an initial captivity of Daniel and friends about 20 years prior to that. The first shall be last and the last shall be first principal is at work here. The first to go into captivity, are held captive for seventy years, as prophesied by Jeremiah. They go captive, then 20 years later the rest of them go. Then, after 40 years, a remnant of the last to go into captivity return; after another 10 years, 70 years after the initial captivity, a remnant of those people return for the rebuilding of the temple. There are 30 years extra of captivity -- compare to the 430 years that the Israelites were in captivity compared to the 400 years that was prophesied to Abraham.
For now, I will look at the captivity dates that Ezekiel talk about, which are the last out and first in. The northern kingdom went into exile about 721 BC (final conquer of the land). The southern kingdom went around 586 BC, approximately 135 years later. They were exiled for 40 years, and then a remnant returned. Meanwhile, the northern kingdom continued their exile for another 215 years. It did not happen that the northern kingdom was exiled for 390 years, and then a siege on Jerusalem occurred while the northern kingdom returned, which is what having 390 years + 40 years would suggest.
721 BC 586 BC 546 BC 331 BC
\ / \ / \ /
135 years 40 years 215 years
135+40+215 = 390 years
Since YHWH's word is true, a remnant of the northern kingdom had to return from exile after the 390 years. This was about 331 BC, about the time that Alexander the Great ends the Persian rule in Israel and brings Greeks to Israel. The Greeks allowed the Jews to run their state. These Greeks were likely in part some of the descendents of the northern kingdom. John 7:35 "Then said the Jews among themselves, 'Where will he go, that we shall not find him? Will he go to the dispersed among the Greeks and teach the Greeks?'" At the time of Yeshua, the Jews knew that the northern kingdom was living among the Greeks. This completes the first 390 year cycle.
However, Jeremiah 16:18 says, "And first I will recompense their iniquity and their sin DOUBLE because they have defiled my land." 390 years x 2 = 780 years. Taking the exile of the Northern kingdom in 721 BC and going forward 780 years, one arrives at about 60 AD. This is the approximate year that Paul appeared before Festus and received as many as would come. Paul's ministry was primarily to the Gentiles, many of which were northern kingdom exiles. Just as there should be a return from exile at that time for the northern kingdom, as in the first cycle of 390 years, there should be a return of Jews from exile about 215 years prior to that, which is about 156 BC. This is the approximate time that Jonathan the Maccabi is established in Jerusalem, the temple mount is repaired, and the Hasmonean Jews rule over Judea, Gezer, and Jaffa.
Leviticus 26:17-18 speaks of seven cycles: "And I will set my face against you... and if you will not for all this hearken to me, then I will punish you seven times more for your sins." 7x390 = 2730 years. 2730 years from 721 BC is about 2010 AD, which is about now. Therefore, at this time we should be seeing the first remnant of the northern kingdom returning to Israel soon. Likewise, backing up 215 years again, we should see the southern kingdom have a remnant return. Looking at history, this is the approximate timing of Napoleon's manifesto promising the Jews return to their land.
Given these three witnesses of scripture and history, my perspective is that Ezekiel lay on one side for about 135 days, the last few days of which he was staging his siege. After the approximate 135 days and siege were completed, he lay on one side, and then turned to lay a second time (sheni), which he did for 40 days, turning from side to side each day. After Judah's 40 days were completed, Ezekiel lay on one side only for the remaining 215 days. This would total 390 days, allowing enough time between dates on a lunar or solar calendar without any intercalation in either system. This would, therefore, not be a passage sufficient to support a lunar calendar theory, especially considering there are already so many witnesses against it as listed above.