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The Myth of the 360-Day Calendar in Scripture

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For many centuries, students of Scripture have sought to understand the calendar of the Bible. Many have attempted to say how old the earth is in years and claim they got their numbers from Scripture. Most famously, James Ussher even attempted to give specific dates for some events.

I wish to make it clear that this article and my research are not meant to be a criticism of anyone who has attempted to make sense of the numbered years in Scripture. I simply wish to point out that the current prevailing theory, that the Bible’s calendar has 360 days in a year with 12 consecutive 30-day months, has no significant supportable basis in Scripture. It is assumed by seminaries, Bible colleges, and is part of the fabric of many articles published by Creation Science organizations.

As we shall see, the calendar most consistent with Scripture likely has a total of 364 days in a year. The 364-Day calendar can also be shown to be the digital engine that drives the 52 consecutive 7-day weeks of the Gregorian and Julian calendars in use today. This 364-Day calendar follows the general rules of a Hebrew calendar and also has matching Gregorian dates that never change from year to year.

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It is very important that the reader understand that this 364-Day calendar, consistent with Scripture, is not the currently used secular Hebrew calendar that is based on solar and lunar cycles. On this immutable 364-Day calendar, September 13 is also Tishri 1 and always falls on a Friday. On the current secular Hebrew calendar, Tishri 1 never falls on a Friday.

I hope to demonstrate how using these pieces of the Bible chronology puzzle, allows us to date the events of the Bible, as well as connecting them to our Gregorian calendar using a mathematical formula calculating the Gregorian date of the death of Adam in Genesis 5:4-5.

Some Objections

One of the two most common Scriptural arguments for the 360-day year comes from the Book of Genesis. According to Genesis 7:11, it begins to rain seven days after Noah and his family enter the Ark.

In the six hundredth year of Noah’s life, in the second month, on the seventeenth day of the month, on that day all the fountains of the great deep were broken up, and the windows of heaven were opened.

According to my calculations on a 364-Day calendar, that day would be Wednesday, November 6−Heshvan 17, 2458 BC. In the Book of Genesis, Heshvan is the second month on the Scriptural Hebrew calendar. On a Gregorian solar calendar, the same event would be dated Wednesday, March 26−Nisan 6, 2449 BC.

It is obvious from this one example that the 364-Day calendar in Scripture is not a solar calendar like today’s Gregorian calendar.

This “seventeenth day of the second month” is Day 1 of the 150 days that the waters prevailed on the earth.Genesis 7:24-8:4.

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  • The rain falls for 40 days and stops.
  • The water covers the earth for another 110 days before beginning to subside to a level where the bottom of the Ark makes contact with land in the mountains of Ararat.

These verses make it clear that the Ark comes to rest on day number 150 in the seventh month, the seventeenth day of the month, on the mountains of Ararat.

Day number 150 on the 364-Day calendar would be Friday, April 4−Nisan 17, 2457 BC. This same event happens on the Gregorian calendar on Friday, August 22−Elul 7 in 2449 BC.

For those using a 360-day year with 12 consecutive 30-day months to date events in Scripture, they have a mathematical dilemma with these verses.

If the rain starts on the seventeenth day of the second month and stops on the seventeenth day of the seventh month, and every month has 30-days, then Nisan 17 is day number 151 in the seventh month in the Book of Genesis.

Using the example above and a Hebrew calendar, in which the fourth month of Tevet always has 29-days, then Nisan 17 falls on the 150th day, in accordance with the Biblical text. Months two, three, five and six on the Hebrew calendar, have 30-days each.

The Hebrew months of Tevet, Iyar, Tammuz and Elul always have 29-days, even if it is a leap year, according to the secular Hebrew calendar in use today. The other eight months have 30-days each for a total of 356. These are some of the basic guidelines that define any Hebrew calendar whether solar or non-solar.

To arrive at my conclusion of a 364 day calendar we add to these the Sunday to Sunday days of Creation Week.

Eight days are needed to make seven consecutive 24-hour Hebrew days because the Hebrew day starts six hours before the normal solar day at 6 pm the previous evening.

The Days of Creation Week have no corresponding days on the Hebrew calendar and must be added to it. These eight days are inserted between the end of the first Hebrew calendar month of Tishri and the beginning of the second month of Heshvan on the Genesis version of the 364-Day calendar. On our modern Gregorian calendar, these corresponding eight days are digitally generated from October 22-29 in the special solar year of 4101 BC.

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On the 364-Day Bible Reference calendar, these eight days always fall on Sunday through Sunday from October 13 through 20.

Additional examples

Some other verses used to conclude the Bible uses a 360-day calendar come from Revelation 11:2-3 and 13:5, which mention a period of forty-two months. In these verses, the forty-two months are described as a period of 1,260 days. This time period involves the events of the final 3.5 years (42 months) of the future Great Tribulation.

At this point, I will avoid the many different theological interpretive issues regarding these verses. I will attempt to explain these seemingly “mysterious” numbers. This period of Tribulation is also mentioned in Matthew 24:15 and in Daniel 9:27 and 11:31. Adherents of this 360-day theory rarely mention Daniel 12:11-12, involving 1290 days and 1335 days, which are more easily explained by the 364-Day calendar.

The extra 45 days when added to the 1290 days could be made up of the additional 14 days that would be added to 3.5 years of a 360-day calendar to make the 364-Day calendar plus one month of 31 days.

There is no reason we are forced to conclude the number of days and months used in the Biblical text dictate a 360-day calendar with 12 consecutive 30-day months. The 42 months of 1,260 days could be better described as a Hebrew calendar year with four months of 31 days, four months of 30-days, and four months of 29-days. Such a calendar would at least give the four months of 29-days required for a typical Hebrew calendar. But this does not work because there are no 31 day months on a Hebrew lunar calendar.

It appears these verses are writing about the same future events. This may be new to you to think Scripture could be so precise. Isn’t it possible Scripture means exactly what it says? Could it be that the inspired writers of Scripture were simply stating the exact number of days given to them by God who is the ultimate Author of the text?

To my knowledge there is no clear attempt to explain the number of days in each month of the biblical calendar. And, just because 1,260 can be divided by thirty 42 times does not mean that every month must have 30-days. We have seen this wasn’t true in Genesis and we need not assume so in Revelation or any other part of Scripture. There is no known sacred or secular Hebrew calendar following this pattern.

Any Hebrew calendar has four months that always have 29-days. If someone wanted to make the case that a 360-day calendar had four months of 29-days, four months of 30-days and four months of 31 days, such a calendar could be a Hebrew calendar—if a Hebrew calendar were allowed 31 day months. All that would be needed is to come up with a name for the four extra days since the Hebrew calendar only has 356 days to work with.

It is not surprising that no one seems to have come up with an example of what this 360-day calendar looks like. A 360-day calendar cannot be connected to either lunar or solar cycles. The days of the week would not be the same every year unless you went to an 8-day week that repeated 45 times a year.

The only way anyone can make a case for 12 months of 30-days is to show that the calendar of Scripture is not connected to any known Hebrew calendar.

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Written by Jim Liles

Jim Liles-The Timeline Guy is the Author of Earth's Sacred Calendar: The Dated Events of the Old Testament. This book shows the inerrancy of the dated events in Scripture from Creation in 4115 BC to the Crucifixion of Jesus in 30 AD. This unique Bible Chronology and other download files can be found at The Sacred
. Jim is also President of 'The Sacred Calendar' - a 501c3 Non-Profit organization in California.

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