Everyone knows there are 365¼ days in a year—except, seemingly, the Bible... In both Genesis and Revelation, there are 360 days in a year and 30 days in all months. You won’t find the 365¼ day year and alternating 29 and 30 day lunar months we see today. Does this mean the Bible is an inaccurate book (as skeptics believe)? Not in the least. Read on to find out the little-known calendar secret of ancient history from Genesis and also Revelation’s hidden prophecy about earth’s change to a 360 day year because of a global catastrophe—before the rapture.
One Tribulation, Three Lengths?
The Book of Revelation contains many insights and predictions to encourage, thrill and scare you. Some are plain and obvious; others are subtle and hidden from most, only to be found by the few inspired to dig deeper (Dan 12:4, 9-10; Rev 1:1-3).
For example, that an evil beast-like ruler will dominate the entire earth (Rev 13:7) for the last 42 months of this age (Rev 13:5) is plain and easy to understand. That a major change to earth's orbit is predicted by this and related numbers is not obvious at all.
What numbers? Curiously, there are three different time lengths implied for the great tribulation found among six accounts of activities taking place then:
1. 3½ Years / Half of 7 Years
Daniel 9:27 tells us that the Abomination of Desolation and ceasing of the daily oblation will happen in the "middle" of the 70th week (or final 7 year period) not in the beginning of it. Jesus also says at the time of the Abomination of Desolation that it will be urgent to head to the place of safety (Mt 24:15) as "great tribulation" follows it (Mt 24:21). Half of 7 years = 3½ years.
Daniel 7:25 says that the Little Horn (Antichrist) will speak against God and oppress the holy ones for a time, (pair of) times, and half of time or 1 + 2 + ½ = 3½ years
Revelation 12:14 says that the Woman is protected from Satan for the same amount of "times" (3½) as the Little Horn oppresses = 3½ years.
2. 42 Months
Revelation 11:2 says that Gentile armies will trample Jerusalem for 42 months.
Revelation 13:5-7 says the Beast (Antichrist) will blaspheme God and conquer the saints for 42 months.
3. 1260 Days
Revelation 11:3 says that the Two Witnesses prophesy during this same period for 1260 days.
In other words, the 1260 days of the Two Witnesses is the same 42 months that the Temple Mount is trampled while the Little Horn/Beast speaks against God and oppresses the saints (Rev 11:1-3=Dan 7:25=Rev 13:5). It is also the same 3½ years that the righteous "Woman" is protected in the wilderness (Rev 12:14). All these events relate to the tribulation when the Antichrist continues for "a time, (pair of) times, and half a time" as Daniel 7:25 says.
Is this consistent repeated length of 3½ years for the tribulation surprising to you? I can appreciate if it is as most Christians have been taught that the tribulation or great tribulation is seven years long."
However, as you can see, the only time "seven years" is mentioned in connection with the great tribulation is for entire seven year 70th week. The great tribulation is only the second half of that. The first half is not called "the tribulation" also but has another name given by Jesus: the "beginning of birth pains/sorrows" (Mt 24:8; Mk 13:8).
By the way, if you doubt that a basic math error of this kind could really creep into Christian doctrine, then consider how there are not "three days and three nights" (Mt 12:40) between a "Good Friday crucifixion" and an Easter Sunday resurrection! [1]
The Hidden Prediction in Great Tribulation Lengths
So, why do Daniel and Revelation give us three different measurements of length for the same time period when all that was necessary to establish the length is to use one measurement such as "three and one half years?"
Good question. The answer will begin to take shape once we do a little math on the numbers above:
- 1260 days ÷ 3.5 years = 360 days per year
- 1260 days ÷ 42 months = 30 days per month
Obviously, this does not match our current cosmology of:
- 365.2422 days per year.
- 29.531 days per lunation. The Hebrews used lunar months, or the cycle from new moon to new moon. This is reflected in the Hebrew word for month (chodesh) meaning also moon, similar to how the etymology of "month" is related to the moon.
It is also a mismatch of both the (fixed, precalculated) Rabbinic Jewish and (observed, lunar-agricultural) Karaite calendars of today. Both of these calendars have 29 day months mixed in with 30 day months instead of consistent 30 day months. Since this amounts to around only 354 (not 360) days per year, every two or three years a 13th or leap month (Adar Bet) must be added to intercalate the calendar (keep it in sync with the seasons).
Given that a 360/30 calendar does not match our 365¼/29½ reality, it is very tempting to dismiss the great tribulation numbers above as not intended literally, but as convenient approximations.

"Depart From Me, I Never Knew you!" - Jesus
Jesus predicted that he will tell many sincere believers to basically "get lost" instead of welcoming them into the Kingdom. So...who are they and what did they miss or do wrong? In this study, get those answers and the one requirement for salvation Jesus taught (that Christianity misses) so that you can make sure you don't hear these dreaded words yourself! [2]
But again, why even bother to give these redundant "approximations" if all we needed was to have any one of these lengths to give us an idea of the breadth of the reign of the Antichrist?
If it means what it literally says, then what we have hidden in those numbers is an implied prediction of a coming change of the calendar through a shortening of the year by five days before the Great Tribulation begins. In other words, the earth's orbiting time must decrease around 1% by the time the Antichrist takes power to shave five days off the year.
But how?
The 360/30 Calendar in the Old Testament
Is that even possible? Yes, it is not only possible, but it appears to have happened before(!).
Most educated people assume that the earth has been going around the sun the same way for thousands or even billions of years. They are not aware of catastrophism [3] or the theory that the earth has been affected by sudden violent planetary-wide events in the past. (Immanuel Velikovsky was one of the more noteworthy proponents of this view with his book "World's in Collision.")
Catastrophism should not be a strange concept to those who have read the Bible. The deluge in Noah's day was just such a thing.
Even atheists commonly accept that the dinosaurs were wiped out when an asteroid or comet struck the earth. That, too, is catastrophism—and of a kind that could explain how the calendar of the earth could change and probably changed before.
You see, the Old Testament implies that the Hebrews and other ancient peoples knew nothing about the 365¼/29½ cosmology of today. The implication is always a 360 day year and 30 day month. Some examples:
- Noah's Flood: During the time of the flood Genesis tells us that 150 days started on the 17th day of the second month, and ended on the 17th day of the seventh month or exactly five months later (Genesis 7:11, 24 and 8:3-4). 150 days ÷ 5 months = 30 days per month. 30 days × 12 months = 360 days per year.
- Month Of Mourning Statute: Mourning for the dead is ordered for a "full month" and is recorded as carried on for thirty days (Dt 34:8; 21:13; Nu 20:29). If it were as today that some lunar months were 29 days and others 30 days, why is there never a record of a 29 day month anywhere in Scripture but many accounts of 30 days? (In fact, the number 29 never appears in the Bible.)
- King Ahaseurus' 180 Day Feast: Esther 1:4 implies a 360 day year or consistently 30 day month by recording that the feast continued exactly 180 days. Whether the feast is meant to fulfill half a year or six months, neither approach would arrive at 180 days under a 365¼/29½ cosmology but both approaches would work under a 360/30 calendar.
How the Original 360 Day Year Lengthened to 365¼ Days
The Bible is not the only ancient testimony we have of the ancients living in a world of 360 day years and 30 day months. There is much historical evidence from ancient history that we were on a 360/30 calendar once before; (from which we get our 360 degrees of a circle). In fact, there are over a dozen ancient calendars with 360 day years or 30 day months before the 8th century BC [4].
After that, the calendars changed. Did something happen in the 8th century BC to require calendars to be updated?
From Chuck Missler I first learned an answer to this question. There is evidence that Mars used to be on a different orbit that brought it dangerously close to earth. Chuck Missler talks about how it came so close it brought catastrophes with semi-regularity. From this past we may have much of the dread and ferocity associated with the name Mars (as in "martial arts"). In the last interaction with earth, it both modified earth's orbit and its own so that it has the present "safe" orbit seen today.
But what about the 30 day lunation becoming 29½ days?
If Mars perturbed the orbit of the earth to move further away from the Sun and take five days longer, then automatically the lunar cycle would shorten from 30 days to the current 29½ [5].
If you are as fascinated by these ideas as I am, then I suggest reading the book The Mars-Earth Wars [6] for more details.
The Solution: Wormwood Catastrophe Before the Great Tribulation
If Mars is now in a different orbit which never brings it close to earth anymore, then it is not likely to reverse what it did before to our calendar. However, there is another object mentioned by Revelation that can make this calendar reversal right on time for the great tribulation.
The great tribulation of Daniel is also described in Revelation; from the 5th trumpet through 7th trumpet. Not surprisingly, the 3rd and 4th trumpet describe global catastrophic effects—polluted fresh waters and a "nuclear winter"-like darkening of the sky, respectively—blamed on a wayward "star" called Wormwood.
What is this Wormwood and how could it work?
It's important to note that the Greek word aster translated "star" in English Bibles is not specifically a star but refers to any unknown object in the sky whether it be a meteor, asteroid, moon, star or planet. While a star could not come anywhere near earth let alone "fall upon" it and an asteroid is too small to affect earth's orbit, a dwarf planet would explain all the catastrophic events described by Revelation as leading up to the Great Tribulation.
For example, before Wormwood is mentioned at the 3rd trumpet, the 1st and 2nd trumpets describe a storm of meteorite and asteroid impacts on the earth. This would readily contaminate fresh water with everything imaginable. The resultant impacts would also send particulate into the atmosphere. Both of these impact results readily explain the 3rd trumpet poisoned waters and 4th trumpet blocked sunlight, respectively.
Before all that, the 6th seal describes a great global earthquake and multiple eclipses with a meteor shower. How do we explain that?
Again, a dwarf planet passing close enough by the earth would send strong gravitation waves causing earthquakes. If it was smaller than earth and passing at earth's Roche Limit [7]), it could be overcome by earth's gravity and disintegrate. This would explain the overwhelming amount of meteorites and asteroids described in the 6th seal, 1st trumpet and 2nd trumpet. (I say overwhelming because the 1st trumpet says all the grass on earth is burned up by the burning meteorites. That's one massive meteorite storm!)
Finally, Wormwood would have itself tugged back at the earth to not only cause the global earthquakes, but it would also "perturb" earth's orbit enough to shorten our year to the 360/30 calendar that begins at the 5th trumpet or Great Tribulation. This will require moving the earth into a closer or smaller orbit with the sun.
"What About A Glancing Blow?!"
One of the theories you'll hear among Christians to explain end time prophecies like "unless those days had been cut short no flesh will survive" (Mt 24:22 KJV) is that the length of the 24 hour day will change (yes, I'm not making this up). People suggest this for to explain the 1260/1290/1335 day periods, as well, since they clearly imply a change of the calendar in some way. Someone even emailed me to suggest how that change could be effected:
I think you may be mistaken to believe that the earth’s orbit speed will be increased in order to shorten the orbital year to 360 days. One point to consider as an argument against that theory is that the lunar month will not necessarily change if earth is given a "boost" by Wormwood. I believe that it is more likely that the earth’s rotation about it’s axis will slow down as a result of Wormwood striking a glancing blow from east to west.
If you give this theory just a moment of critical thought you'll see how it simply does not work. The 24-hour day is a result of the earth spinning at 1000 miles per hour. To shorten the day, you have to speed up that spinning. A "glancing blow" from an asteroid would accomplish this instantaneously and the results would be beyond catastrophic. They would be fatal to all. The sudden change of rotational speed would send all lifeforms and objects spinning at 1000 miles per hour flying into space compared to the new increased speed of the earth. It does not work. What a bizarre theory.
What I'm proposing is much more gradual. Wormwood and earth do not collide like two billiard balls. It gradually approaches earth, tugs on it and breaks up as a result of Earth's reciprocal and greater gravitational tug. Earth wins, but is perturbed from its orbit enough to effect a faster orbit and reduction of 5¼ days to the year. Many pieces of Wormwood "fall upon" the earth (Rev 8:10) but their effect is not one of complete destruction but much less, affecting one third of the fresh water (Rev 8:11).
How the Antichrist Really Comes to Power
What will the result of this be? The world will be a shell-shocked. Civilization will be smashed. The lights will be out. Homes will be flattened from the earthquakes and impacts.
All the food will be burned up, buried or contaminated with no hope of growing more with the diminished sunlight.
People will literally be starving to death in the cold. Those with food will be killed for it by stronger gangs. It will be total chaos and hopelessness.
The world will need a "strong hand from somewhere" to restore order, shelter and food production.
This is exactly when the Antichrist appears and offers a solution. With the power of Satan (2Th 2:9) he is able to convince the world that he is God himself (2Th 2:4) and the only one capable of fixing the mess...for a price (the mark of the beast).
And part of what he will be fixing is the calendar. Out with the 365¼ day year, in with the 360 day year (Dan 7:25 ?).
For how you will survive Wormwood and escape the Antichrist, see my article on Faith to Escape. [8]
The 360 Day Calendar Works Today? (or 360calendar.com Debunked!)
One reader of the original article above commented as follows:
I don't believe in the Nemesis theory (although the Melancholia movie was pretty cool). With the recent comet and asteroid fly-bys, I could definitely see a comet or meteor hitting Earth soon.
The Hebrew calendar has 360 days, and then adds an extra month (360calendar.com). Every 40 years the number of Hebrew calendar days equals the number of Gregorian days. Since the Hebrew mind might consider the basic year to be 360 days, I don't see a need for a catastrophe.
The 360calendar site overwhelms visitors with all kinds of tables and figures to convince them a 360 day year calendar works on today's 365¼ day solar year calendar with the addition of a 30 day leap month every six years (or so). As such, few readers will be able to catch two crucial flaws with the site author's attempt to explain away that the 360 day year of the Bible is based on a 360 (not 365¼) solar year at that time:
1. This thirteenth month he requires is never mentioned in the Bible! Out of dozens of dates described in the Bible, including all twelve months of the year, there is no date for any event in a "thirteenth month." It is completely unknown in the Biblical record. If an adjustment to the solar calendar by a thirteenth month was the practice in Biblical times, there ought to be a mention of the practice or at least a date using it. We have neither. With no mention of a thirteenth month, it is only justified to assume a year of twelve months in Old Testament times (at least up until the time of Hezekiah when the calendar finally changed to what we see today requiring a thirteenth month). [9]
2. He completely ignores that a 30 day lunar cycle is required by the 30 day biblical month which does not match the current 29½ day lunar cycle! Months in the Bible were moon-based [10] (Ps 104:19), just like the Islamic and Jewish calendars are today. Rather than being arbitrary counts of days out of sync with the moon like our Gregorian calendar, they began at the new moon. The Hebrew word for moon, month and new moon day are all the same in biblical Hebrew: chodesh.
Thus, the 360calendar model only works if you invent a thirteenth month and ignore the 30 day lunar cycle required by the 30 day biblical month. The model fails to explain how Genesis and Revelation can refer to a 360 day year and 30 day (lunar) month. Conversely, the catatrophism model explains how an original 360/30 cosmology changed around the 9th century BC when a dozen 360/30 ancient calendars changed...and how it can change again from our current 365¼/29½ cosmology back to 360/30.
People may not believe Wormwood is literal or see a catastrophe as necessary to explain the 360/30 calendar of the Bible, but the fact remains that Revelation (from the 6th seal through 4th trumpet) already literally describes and predicts a series of grave global catastrophes that include deep impacts and other evidence of a close flyby from a visiting body including a global earthquake and double eclipses. Instead of the iffy "Nemesis theory," call this the sure Wormwood prophecy.
If according to this prophecy something big is passing that close to send fragments on the earth (meteor shower, meteorite storm, asteroid in ocean) and to cause a great earthquake moving every mountain and island out of place and maybe also cause the eclipse of the sun/moon...it can also explain why the calendar is 360/30 again according to Revelation's description of the Tribulation period that follows immediately after the Wormwood catastrophes finish.
If more people were familiar with catastrophism, the ancient 360/30 calendars and the synchronization of the biblical month with the lunar cycle, less would invent or believe the calendar models like the 360calendar site describes.