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1.   Seeking an Actual Date for the Flood

Genesis Flood "Dates"

Several mysterious time-references are handed to us in the Flood story of Genesis.  Yet like explorers stumbling upon a cryptically inscribed, ancient waymarker to a lost city in the jungle, we stand and wonder at the seemingly overt, yet ultimately hidden meaning.

Two sorts of time information are conveyed in Genesis 7 and 8:

A. Interval:  a number of elapsed days or months
B. Date:  a reference to a unique day of a calendar

To effectively chronicle the destruction that occurred somewhere in the world's dark past, it would have sufficed simply to set forth key events, and separate them using specific intervals (category A).  Indeed, much of the Flood story does appear in this manner.

Yet for some reason, actual-seeming "dates" of some sort (category B) are also provided by God, the ultimate author of the Bible.  Though vague, their conspicuous inclusion prompts the thought:  Did God, who does nothing in vain, include them that we might know, to-the-day, when these events took place?  Indeed Bible students are, in recent years, blessed with a fuller understanding of the timeline of the earth (primarily from the work of Harold Camping), so we know with confidence that the Flood struck in 4990 BC.

Yet the "dates" in Genesis 7 & 8 seem locked in mystery, as their year-components are given relative to a year-system whose base-level, or "starting day", remains unclear.  The goal of our efforts would be to find a way to translate the "dates" we are given in Genesis into references of time which we can understand... to connect the Flood with the rest of recorded history.

In Genesis 7:11a, God inserts the first time-clue:

"In the six hundredth year of Noah's life, in the second month, the seventeenth day of the month,..."

God speaks here of a system of years, divided into months, and then further divided into days.

Seemingly all calendars men have used follow this familiar pattern.

What calendar (if any) does God have in mind?

A Screening of Calendar Candidates

To what calendar is God referring?

1.  A "calendar" based on Noah's life,
commencing with the day of his birth

This notion, by itself, does not help us to determine any alignment with a system of timekeeping we can trace back into history.  Yet this simple answer to the mystery of the Genesis "date" references does make sense, due to its straightforward approach to the wording:  "In the six hundredth year of Noah's life, in the second month, the seventeenth day of the month...."  Further, as we often refer to Noah as one of the "calendar patriarchs" (whose very birth and death dates mark, to-the-day, Biblical periods named for them), his life already serves as a calendar, a ticking timekeeper, of sorts.

There exists one extra, interesting possibility, however-- one that allows us both to maintain this "calendar patriarch" interpretation, while melding it together with another, more historical calendar-- with potential to allow precise daycounts:

What if Noah were born on the first day of the year in some other calendar?  Then any month/day in Noah's life would correspond directly to the same month/day in the other calendar.  This would mend the broken chain of calendars from then until now in at least one point.

Such a deliberate alignment might seem unlikely, or too convenient.  Yet we already know that God deliberately aligned the Flood to commence at 6023 (6000 + 23) years from Creation, and that Noah's age seems to have been deliberately aligned to be 600 at the same time.
Further Validation of Gregorian Dating, about whether Jesus might have begun life in the womb on January 1 of 7 BC, His birth year.)

And such a "convenient" alignment (between Noah's life & another calendar) might in the end prove to be a necessary alignment, to allow eventual disclosure of these otherwise unavailable Flood-date secrets.

(Some have also alleged, that while the "dates" do refer to Noah's 600th year; they are merely referencing dates from an unspecified calendar, occuring at an unknown time during this 600th year.)

Still, a key question would remain:  Which calendar?  Is there a calendar we can find, that is compatible with the Bible's Flood time-clues?

2.  A secret calendar in Heaven

Then what man could know it?  The Flood "dates" in Genesis would be undecipherable information, given for no apparent purpose.  This seems to go against Scripture:

Luke 12:2  For there is nothing covered, that shall not be revealed; neither hid, that shall not be known.
Amos 3:7  Surely the Lord GOD will do nothing, but he revealeth his secret unto his servants the prophets.

Let us look instead to some actual calendar schemes that men have devised and used over time.

3.  The celestial motion of the moon

The moon, though a mystery to many of us, does define a definite cycle which was unquestionably known by those of Noah's time.  (See this site's  Lunar Motion and Data  for an easy, yet thorough explanation of what the moon is doing.)

Indeed the actual moon-phases for any time in 4990 BC can easily be calculated today, by starting with the moon's present-day phase, and working backwards, using its well-defined cycle-length.

Without known exception, lunar calendars have used the new-moon phase to start each new lunar month.  It is then that it seems to be "born"-- indeed, the Hebrew word for "new moon" (molad) means "birth".

If Noah (and/or God) were marking time by the moon, then the phrase "in the second month, the seventeenth day of the month" would mean seventeen days into a moon cycle (in other words, the sixteenth day after the date of the most recent new moon).

This necessitates a new moon on the first day of "the second month".  (That is, assuming a lunar month with a calculated, rather than an observed, starting day.  See  New Moon , on the Lunar Motion and Data page of this site.)

Yet there were at least twelve new moons in 4990, each potentially marking the first day of some lunar month.  Of these, which was "the second month"?  We will know this, when we first know:  When did this "year" begin?

Was the first month, like our January, a dividing line between growing seasons?  Or did the year commence with the actual planting in the spring?  (Assuming Noah's civilization, like most, existed in the northern hemisphere.)

Thus the moon alone cannot pin down the actual time meant by these "dates".  (Though later, in section #6, we will see how lunar clues may add to the case for another type of calendar.)

Furthermore, the Bible itself seems to have inserted a clue that the dates could not have belonged to a lunar-based calendar:  The five-month span between [2nd month/17th day, Genesis 7:11] and [7th month/17th day, Genesis 8:4] is twice described as a "hundred and fifty days" (Genesis 7:24, 8:3).  Why is this a problem?

The moon's cycle of phases remains constant at approximately 29+1/2 days (29.530588853).  Yet the inexactness of this extra half-day poses a problem. 

Man lives by the sun.  All routine activity-- work, sleep, etc-- is constrained to follow the sun's daily portion of light and warmth.  If man's life did not oscillate to the beat of the complete solar day-- an interval of time which everyone can easily count without dispute or confusion-- then the very concept of a week would be impossible, and the ability to coordinate human activity or make plans into the future would be greatly frustrated.

Thus the rhythmic pattern of lunar change, while fascinating to watch, and indeed useful for its more lengthy measurable interval, could never replace the day as man's primary "stopwatch"-- to the extent that he would reinvent the day, in order to fit the moon's timetable.

Yet there is an easy solution.  The awkward, uneven moonphase period of 29+1/2 days becomes quite manageable when taking advantage of the fact that 29+1/2, doubled, equals 59.  Those who fashion a calendar with months centered on the moon have routinely adopted the simple pattern of one 29-day month, followed by one 30-day month, then a 29-day month, and so on.

This solution allows planning based on days and months-- the days being naturally defined by the Sun, and each month now being divisible into complete days.

29.5 x 2 (two moon cycles) = 59 days
29 + 30 (two adjacent lunar months) =59 days
A nominal 0.061177706 day (88 min.) error accrues every 59 days under this arrangement.  Occasionally, an extra 30-day month can be inserted to compensate.

Given this seemingly unavoidable pattern of lunar month lengths, we can show that there is no way to find five such consecutive months totalling 150 days.  There are few possible combinations to consider...

Five lunar months can contain:

[29 30 29 30 29 = 147 days]
[30 29 30 29 30 = 148 days]

Even with an inserted leap day (required after approx. 32 lunar months), we would still have only 148 days:

[30 29 30 30 29 = 148 days]

The following would not be a logical approach:  there is a two-day gap between 29 and 31, indicating that an error greater than one day existed either before or after the correction:

[30 29 30 29 31 = 149 days]
Even by ignoring the 29-30-29-30 pattern, the math is not favorable to attaining 150 days.  Here is the total for five consecutive lunations:
5 x 29.530588853 days

= 147.652944265 days 

(2.347055735 days short of 150)

Appendix V,  Five Lunar Months?  Further Doubt, also addresses the Lunar and Hebrew calendars in this matter.

Preconceptions to avoid:

1.  Assumptions about pre-Flood man

Was it the fashion of Noah's day to reckon months by passing moons?  Although no one knows, there may be the unconscious assumption that pre-Flood man would have been forced to rely on the moon for timekeeping; being comparatively primitive, concerned with basic survival, and too unorganized to arrive at any alternate system.

Yet this may be an unfair portrait of civilization before the flood, painted in our minds by exposure to evolutionistic fables of primitive early man.

Remember that the fruit of six entire millennia of man's progress and knowledge were erased under massive waters.  Only an unclear fraction of that knowledge, that possessed by Noah and his family, made it through.

Certainly there would have existed much pre-Flood interest and achievement in areas such as mathematics, metallurgy, construction, agriculture, civil engineering; and especially, as with most civilizations, in astronomy.  And with the continents and tongues not yet divided, every insight and advancement could have been pooled together...multiplying the rate of progress.

In the end, we do not know what calendar the old world favored-- a basic lunar model, or one more sophisticated.  We are not entitled to a lesser estimate of them merely from lack of written record; it was all washed away.

Let us move on then to other possible calendars, which may be able to explain five months totalling 150 days-- with confidence in the exactness of this figure, given by God; and in His ability to fit all 150, in some precise way.

2.  Assumptions about Noah and his "calendar"

Keep in mind one very important point:  It should not be assumed that these "dates" from God need come from an actual calendar in use by people of that time, or by Noah himself.  It will be noted later, regarding the Flood "dates", that the "month and day" were outside of Noah's need to know-- not even for purposes of recording them-- for it was Moses, not Noah, who passed them on from God.  They may rather be markers, for us these many years later, to fix the story precisely in time... and learn something from the timelines that can be formed.

4.  The Hebrew calendar

At least five issues of concern present themselves:

   a.  The Hebrew calendar is lunar-based; and, as explained in #3 above (lunar calendar), both the Bible's numbers (five months = 150 days) and the Moon itself (with its fixed astronomical cycles) seem to preclude the use of a lunar calendar in unlocking the flood story.

Appendix V,  Five Lunar Months?  Further Doubt, also addresses the Lunar and Hebrew calendars in this matter.

   b.  The Biblical account of the Flood does not overtly demand use of the Hebrew calendar.  Further, it avoids making even the simplest reference to it:  flood months are named by their ordinal numbers ("second month", "seventh month"), rather than by Hebrew names.

   c.  At the time of the Flood, the Hebrew calendar was not in use... not having been created nor commanded until millennia later.

   d.  It is perhaps debateable whether the Hebrew calendar can lay sole claim to being 'the calendar of the Bible'... considering that the Julian, or "Roman" calendar (near-twin of the Gregorian), was used in New Testament times and lands.

   e.  The Hebrew calendar is not mathematically predictable or calculable, and cannot be extended with certainty into the past.  Two reasons:  1)The priests would decree the first of each month based on observation of the new moon;  2)The priests inserted a leap-month as needed every few years.  Unfortunately, there is no carefully kept history of such priestly intervention, especially in the dim years between Noah and Moses.

5.  A 360-day calendar  (with twelve 30-day months)

The issue with finding five consecutive 30-day months (see Section 3 above, Lunar Calendar) can be resolved by using a 360-day calendar having twelve 30-day months.  Without dispute, 5 x 30 = 150.

To many, this seems proof enough that God is giving us a glimpse at an ancient calendar, and that it was of the form [12 x 30 = 360].

Yet must it be?

If this conclusion is part of current teaching, are we certain it is an inescapable one?

Not only is there another solution, but for many reasons there is a better one.  Section 6 below, Gregorian Calendar, will explain why-- and ask whether any 'ancient calendar' need have been involved at all.

370 Days?

As evidence of a 360-day year, some have pointed to 'the 370 days' between [2nd month/17th day, Genesis 7:11] and [2nd month/27th day, Genesis 8:14].

There is no dispute that this is a span of one year and ten days.  The trouble is, the supposed '370 days' is based upon the unproven 360-day year.  The Bible lacks any specific reference to a literal 370-day interval, or to a 360-day year.  Rather, it names two dates which are simply one year and ten days apart:

      [2nd month/17th day in one year; 2nd month/27th day the next year]

This may deflate the notion that God bracketed the flood story within a 370-day period (...10 [complete] x 37 [judgment]).  However fitting such numbers may seem, it is hazardous to conclude timeline discussion based upon numerical appeal.

Yet it turns out, there is no loss in relinquishing this unsupportable 370-day supposition.

In trying the novel idea of a possible Gregorian connection... that is, plotting the Genesis "dates" directly into the Gregorian calendar (see Section 6 below for this concept and its rationale), we surprisingly trade in this unconnected 370-day "sign", for a series of 3700-day intervals actually tying the Flood to History.  (see diagram in Preface)

This aside, there can still be found 37-based intervals in a Gregorian-based Flood timetable:

375  =  370 + 5  [37 = God's complete wrath or judgment;  5 = atonement (judgment and salvation)].
      Catalog of spiritually significant numbers and their associated themes

There is a 370-day span between the first Sabbath day aboard the ark and the last day:

     [2-23-4990 Sat]  -  [2-27-4989]  =  370

A 37-day interval exists from that first Sabbath to the following pre-anniversary of the Crucifixion:

     [2-23-4990 Sat]  -  [4-1-4990]  =  37

Seeking an historical precedent

At least one post-flood civilization-- the Egyptians-- used a calendar centered on the number 360.  Yet at the end of the 360 days, they would append an extra five days, for a five-day festival celebrating five of their gods.  This annual correction avoided rapid drifting of the seasons (the actual rate is given below). 

Besides, the earliest date associated with this Egyptian calendar is ca. 4236 BC, seven centuries after the flood.  While mathematically, 360 may be more attractive than 365, there is no solid evidence to tie a 360-day pattern to the people of Noah's time.

Certainly they, as any civilization, could time a year to within a few hours, by counting the days between solstices and doubling that amount; or by counting the days beteween the two consecutive first-risings of a prominent star.  Both indicators are quite apparent when away from city lights, buildings, and modern distractions.

(...In case you were wondering, no Hebrew year contains 360 days:  "An ordinary (non-leap) year has 353, 354, or 355 days. A leap year has 383, 384, or 385 days.  The three lengths of the years are termed, 'deficient', 'regular', and 'complete', respectively." [1])

"...But what about Moses' exposure to Egyptian culture?  Wouldn't he have understood a year to be 360 days, giving us the 370-day total voyage? "

Even if we could say that:

a.  Moses (not God) controlled the wording of Genesis Flood-date-info;

b.  Moses were framing these references in terms of an Egyptian "360-day calendar";

c.  The Egyptian thinking was still 360-day-based when Moses was in Egypt learning about calendars;
We still cannot get around the point that Moses, being "learned in all the wisdom of the Egyptians" (Acts 7:22), would certainly have known-- just as the much-earlier Egyptians-- the true shape of that old calendar... and the true year-length... to be  360 + 5 = 365.

Why a push for 360?

For reasons apart from the 150-day dilemma, it may be tempting for Bible scholars to round the actual ~365.25-day year down to 360.  Perhaps this stems from our own bias:  In geography, compasses have 360 degrees.  In math, a 360-degree arc describes a full circle.

Yet these are weak arguments for Bible scholars to gravitate away from 365... especially when they know that the 365 years of Enoch's lifespan, as a picture of a year, sets God's mark upon that number.  They also know that God does things perfectly, and He made the astronomical details of his Earth to be exactly what they are.  Our culture's frequent use of 360 merely says that 365 may have been less convenient for certain purposes, leading some to adopt 360 as an approximation.

Extreme Season-Drift

The actual drift rate is alarming enough to cast doubt that those in Noah's day (or any day) would have endured a true 360-day year:

    Rate of divergence from actual season:
    = |(true days/year) - (360 days)| 
    = |365.24218967 - 360|

    = 5.24218967 days
Note:  The seasons themselves progress at the same rate, as always.  The mis-match is caused when the shorter years run out of named days before the earth completes the last few days of its timed orbit (i.e., its full cycle of seasons).

    Error after 1 360-day year:  

    - The 360-day New Year precedes actual New Year 
      by 5.24218967 days.  

    - The earlier New Year is getting closer to Actual 
      fall; hence named months begin to arrive earlier 
      than their associated seasons.

    Error reaches 1 season (91.31 Actual days) after:  

    (91.31/5.24218967) 360-day years
    = 17.42 360-day years

Ostensibly, calendars arise to serve man.  What people, dependent upon agriculture for survival, would construct such an unhelpful tool?

Drift from true year-count

Assume for a moment that an unwieldy 360-day calendar were actually tolerated.  What would happen as these shorter years went by?  More years (calendar cycles) would be counted and added to history than are actually passing by (season-cycles; orbits;  "true years").

This violates a principle set forth in the Bible, that a year (calendar cycle) and a growing cycle (season-cycle;  true year) are one:

Exodus 23:16  And the feast of harvest, the firstfruits of thy labours, which thou hast sown in the field:  and the feast of ingathering, which is in the end of the year, when thou hast gathered in thy labours out of the field.
Thus the year-count for, say, Noah's life, would be inflated over the actual number of true years.  And which other calendar patriarchs might also have been under this supposed 360-day calendar's umbrella?

  Error rate = [approx 21 days] per [4 true years]

  950 true years = 950 short years + (950/4) x 21 days 
  (Noah's life)  = 950 short years + 4988 days
                 = 964 short years + 308 days
                 = 964 short years + 10 months

This would throw confusion into our timeline of history, which is based largely on the addition of such yearspans.

If Noah was indeed told of the 120 years until the flood (discussion), should he have taken that to be true years (per God's definition, above), or 360-day years ("short years")?

  Error rate = [approx 21 days] per [4 true years]

  120 short years = 120 true years - (120/4) x 21 days 
                  = 120 true years - 630 days
                  = 119 true years - 265 days
                  = 118 true years + 100 days
Should Noah have expected the Flood in 120 true years... or 1 (true) year + 9 months earlier?

A celestial "clock" was ordained

In Genesis 1:14-18 the Sun, Moon and stars are created.  Among their decreed purposes are:  "to give light upon the earth" (Genesis 1:17);  "for days" (1:14);  and "for seasons" (1:14).

Which of these is the arbiter "for years"?

The Sun, obviously, will "divide the day from the night" (1:14).  Also, by regular variations in position when setting (and rising), it is a gauge "for seasons" and "for years".

The Moon, which would "rule the night" (1:14), sometimes serves "to give light upon the earth" (1:15);  also, when used to determine months and special days, it can "be for signs." (1:14);  but "for days",  "for seasons",  and "for years",  the Moon is not indicative at all.

The assorted stars, by disappearing and reappearing annually, join the Sun as indicators "for seasons" and "for years".

Thus God has decreed that the Sun and the stars will govern the year's length.

If the Flood's time-data (the Genesis "dates"; the 120-year warning; Noah's age [600]) are based on a supposed 360-day year... then God would have had to ignore His own clock; change the set definition of a year; and incorporate ambiguous, flawed data into His Word.

This would lead to:

- confusion over which time-clues are 360-bbased, and which patriarchs' ages need recomputing;

- error in the timeline of history, and douubt as to its validity.

6.  The (proleptic) Gregorian calendar

  (our modern calendar, extended backward in time)

...On finding a "winning" calendar

Each of the preceding calendars has been evaluated for:

- a structure that meshes with the Genesis time clues;

- an ability to reliably connect the distannt past with today.

Yet each failed, for various reasons.

Though imagine if one of them had succeeded....

Imagine that, say, the Hebrew calendar somehow did fit the time-clues.  Also pretend for a moment that Genesis 7 had a reference to three consecutive intervals totalling 79 days.  Suppose the Hebrew calendar happened to have three adjacent months of 17, 39, and 23 days, forming not only a 79-day fit, but the only such group in all the calendar's months.

What would we then have conjectured?

1.  The Hebrew calendar might have application proleptically as a key to unlocking the Flood "dates".

2.  It was God who long ago chose this calendar to be a tool of convenience for the graphing of these "dates".

3.  The span of 79 days is to be aligned flush with the 17, 39, and 23-day "mooring points" these hypothetical months provide.

While technically, an offset by +/-16 days could exist without disturbing the pattern-match;  the lack of a clue, however, as to how much offset, would be interpreted as the lack of a reason to insert an offset.

The point is, given enough convincing support, we would be ready to apply a "new" calendar to an "old" point in time.  We would begin checking for dates and intervals and patterns that might exist, and look for confirming hints hidden within the structure of the calendar itself.

Yet in reality, the Hebrew calendar failed in our examination.

Initial concerns

There are several inevitable points of doubt to be addressed:

1.  The Gregorian calendar seems too far removed from the Bible; too secular.

The same Rome that initially crafted this calendar was also the ruling power in the time of Christ.
Romans 13:1  Let every soul be subject unto the higher powers.  For there is no power but of God: the powers that be are ordained of God.
Luke 20:25  And he said unto them, Render therefore unto Caesar the things which be Caesar's, and unto God the things which be God's.

God uses Roman time for recording Jesus' appearance before Pilate (John 19:14).
2.  The Gregorian calendar seems too modern to even be considered.
Considering its centuries-long persistence from the time of Rome, this slightly-adjusted Julian calendar has proven stable and reliable, and stands unrivaled as the world's standard calendar these twenty centuries later.

It is an interesting prospect, that the same people who united the world with highways and a common language... may also have unknowingly constructed a tool for unifying all of time.
3.  But, won't we need to decode or transpose these dates somehow, coming from an unknown system of time?
If there is no need to transpose dates and clues to achieve a fit, why transpose? 

And if there were an unknown system of time-- then for us to know it, would require either direct revelation (forbidden by Revelation 22:18,19), or the unearthing of a Rosetta Stone equivalent-- but that has not appeared.

The recently-assembled timeline of history was put together with knowledge found in the Bible.  The answers suggested in these studies are obtainable by anyone with a Bible, a calendar, and a pencil.
4.  Actually, aren't these dates simply the years, months, and dates since Noah's birthday?
It does seem that way from the wording, and perhaps this is so.

Yet there is always the possibility that Noah's birthday fell on what would have been January 1.  If true, the dates can be taken at face value.

Regarding January 1 in general:  A pattern has emerged, whereby certain key Biblical dates are noticed spaced at interesting intervals from January 1 of various years, seeming to tie our own modern calendar to Biblical history*.
* see
Benchmark Dates, from the study Further Validation of Gregorian Dating, also on this website.
5.  Certainly this has been checked out before now.  Shouldn't it be harder to figure out than this?
Not if God has hidden it in plain view.

Daniel 5:8  Then came in all the king's wise men: but they could not read the writing, nor make known to the king the interpretation thereof.

Luke 24:45  Then opened he their understanding, that they might understand the scriptures,

Remember, our current knowledge of Biblical times and dates is a recent discovery, and few in our world seem to show any interest.  There is not a host of mathematicians and scholars working on these numbers.

It is not hard for God to hide something when no one is looking for it.
6.  The dates this calendar assigns weren't the actual dates back then.
Precisely.  But that doesn't matter.  Dates are only names; the important things are Events, and the Time-spans between them.  We know that time is very important with God, and He weaves into its flow many intricate patterns.  By using a single time standard across all history, patterns will emerge and computations will be simplified.
7.  I don't know; so much time has passed between then and now....  How can we be certain that somewhere along the line, years didn't get added in or left out-- due to "season drift"?

What if people in different places had different counts, or didn't have pens and pencils, or were too busy finding food and not getting eaten themselves?  What if no one thought to count the days, or they just forgot to count them?

I myself don't go a week without mixing up the days. There were sure to have been disputes and differing counts. What confidence can we have that all that time has been accurately handed down?
Man can roughly gauge the year by passing seasons; but he can also time it with great precision by following the sun, as it sets further to the right, then to the left of true west, over a yearly cycle.  This action is actually quite apparent to anyone having an unobstructed view, and no modern distractions.

Man is also tied to agriculture.  When forced to choose between following a faulty calendar, or avoiding season-drift, he will naturally choose what benefits him.  There is plenty of time to correct a nearly-accurate calendar before much season-slippage occurs; years do not go whizzing by so fast that man cannot adjust, creating entire year(s) of deviation between counted years, and true years.

Of all the things civilizations occupy themselves with, time passage is universally of prime interest-- they do not "forget to count".  If the seven-day cycle of weekdays-- much more prone to error than years-- has been handed down without break, then we can have confidence in longer periods of time, such as Year.

Further-- if God intended us to comprehend and compute time, then surely He could have ensured a reliable chain of custody for the elapsed time on Earth.
8.  Wouldn't God stick with the Hebrew calendar to encode time in the Bible?  If it places "the second month" in the spring, don't we have to go with that?
The Bible is not tied to any one system of time measurement.  Examples:

Hour:  Crucifixion accounts draw on both Hebrew and Roman definitions of "hour":  Although Jesus stood before Pilate at "about the sixth hour" John 19:14, afterward He was crucified at "the third hour" Mark 15:25.

Month:  The fact that the five months of Revelation 9 encompass 153 days ties them to the Gregorian calendar, the only calendar in view where said daycount and month-count can align.

Such precedents should prompt interest in seeing what other time-clues were meant to be unlocked by this calendar.

The Gregorian calendar being thus nominated, we shall now see whether this system of time measurement can pass the same tests that the others have failed.  Our companion concern will be the placement of possible dates, beginning with the Flood.

(a)  150 Days = Five months

The flood story refers to "an hundred and fifty days" which occurs from [2nd month/17th day, Genesis 7:11] and [7th month/17th day, Genesis 8:4].

Oddly, there is a way, and only one way, for the Gregorian calendar to fit 150 days using exactly five months.  This occurs from (any date in) February to (the same date in) July, which interestingly are also the Gregorian "second" and "seventh" months.  [4990 BC is not a leap year, thus yielding 150 days]

_____F i v e   M o n t h s,  i n   D a y s______
  ______      ______ 
 | Any  |    | same |    
 | date | to | date | =   Daycount  (Leap year)
 |_in___|    |_in___|

   Jan    to    Jun   =   151 days  (152)
  *Feb*   to   *Jul*  =  *150*      (151)       
   Mar    to    Aug   =   153
   Apr    to    Sep   =   153
   May    to    Oct   =   153
   Jun    to    Nov   =   153
   Jul    to    Dec   =   153
   Aug    to    Jan   =   153
   Sep    to    Feb   =   153
   Oct    to    Mar   =   151       (152)
   Nov    to    Apr   =   151       (152)
   Dec    to    May   =   151       (152)

Associating Feb-Jul with the "five months" of Genesis suggests the idea of plugging the Flood "dates" directly into our (proleptic) Gregorian-based calendar... to see if any meaningful patterns result.

150-Day Gregorian fit was not by man's design

The suspicion may arise, that religious men of old so architected the Gregorian calendar, expressly to accommodate this 150-day timespan.  As it turns out, the months and their assigned lengths (31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31) (the key to this unique 150-day fit) were inherited from the Julian calendar.  This was created by the pagans of pre-Christian Rome; men who were certainly not concerned with the time structure of an old Hebrew flood legend.

It can be shown that the month-lengths were ultimately shaped to feed the vanity of men.  The following paragraph was taken from an online article:

"In the distribution of the days through the several months, Caesar adopted a simpler arrangement than that which we have now.  He had ordered that the first, third, fifth, seventh, ninth, and eleventh months, that is January, March, May, July, September and November, should each have thirty-one days, and the other months thirty, except February, which in common years should have only twenty-nine days, but every fourth year thirty days.  This order was interrupted in 8 BC to gratify the vanity of Augustus, by giving the month bearing his name as many days as July, which had been re-named after the first Caesar during 44BC.  A day was accordingly taken from February and given to August; and in order that three months of thirty-one days might not come together, September and November were reduced to thirty days, and thirty-one given to October and December." [2]

The outcome of this strife was the seemingly random pattern of month-lengths that we now struggle to remember today.  Yet this pattern produces one, and only one, possible span of five months totalling exactly 150 days.  Add to this the curious fact that the months framing this window are the same, in both time-schemes:  #2 and #7 months (Gregorian); "second" and "seventh" months (Genesis).

Could God have guided the shape of this calendar's month-pattern... so that the "key" in Genesis (the 150-day block) will fit into one, and only one, month-wide slot in the Gregorian?  Thus if He is identifying the Genesis 150 with the Gregorian 150, then we have complete or partial overlap between the Genesis 2nd and 7th months... with all or part of our February and July:

     | 2nd Month |                        |  7th Month  |
     |           |                        |             |
     |     17<---|-------150 days---------|---->17      |
     |           |                        |             |

| February? |                        |    July?    |
     | February? |*                       |    July?    |* 
          | February? |                        |    July?    |

 *Maximum days when [Feb = "2nd mo."] AND [Jul = "7th mo."]  =  28

(b)  Which February day is "the 17th day"?

If, as suggested above, the 150 days start somewhere in February 4990, then there are 28 potential starting dates.

Lacking any direction how February and the second month match up, we entertain the possibility that this is not a missing piece of information; but that it never existed.  After all, to identify [five months] with another [five months] does introduce an expectation of direct alignment unless otherwise specified.

Thus February 1 might be 'the 1st day' of 'the 2nd month', February 28 'the 28th'; but is March 1 'the 1st day' of 'the 3rd month'-- or 'the 29th day' of 'the second month'?

Again, our only hope is to make the same type of tentative assumption that the month-lengths are not hidden, but merely match up with the Gregorian pattern.  Only then can we hope to plot all the time clues, establish the year length, and chart the entire voyage.

The dates 2-17 and 7-17 are considered below in A Possible Date for Creation.

If in fact 2-17 = "the 17th day"/"the 2nd month", we could place Noah's birthday on 1-1.  This possibility was entertained above.

(c)  Lunar activity near the Flood

It can be shown by calculation that there was a new moon on 2-1-4990 BC. [3]  While not put forth as an endorsement of the lunar calendar as basis for the Genesis "calendar", this one correlation between the Gregorian calendar and the celestial clock-- that Noah's flood month (Gregorian-wise) began with a new moon on the 1st-- may serve as a linch-pin between Genesis and Gregorian, showing we are on track.

While we cannot prove the flood occurred in this particular month in 4990, Noah was indeed alive in February 4990.  And if he reckoned time by the moon, then for these 30 or so days his lunar "first" was our Gregorian 1st, his tenth was our 10th, and his seventeenth was our 17th.  This is so, regardless of what name he called this month, or what number he may have assigned to this month.

Admittedly, the flood's other (Gregorian) months could not all begin with a new moon.  So lunar-day-numbers would not line up with Gregorian-day-numbers for these other months in the story.  But it is this critical "second month" that is key-- containing the first two "dates" in the account, and the most startling:  7-Day warning (2-10); and Waters unleashed (2-17).

(d)  Whose dates  are  these?

One major psychological hurdle to clear is the notion:

   "These are Noah's dates.  They didn't have our calendar back then."

Correction:  the dates are not really Noah's; They are God's.  Given to Moses, and finally to us.  And it is not until now that these "dates" can hope to have any useful meaning, as we finally come to understand Time (4990, 2011) and judgment (Flood + 7000 = End).

One must realize that the dates of events had no bearing on Noah:  he did not record them for us, neither had he any need (or likelihood) to even be aware of them, as events played out around him, beyond his control.

Notice that the only time-clues the Bible records him being informed of were intervals, not dates:  "for yet seven days"; "forty days and forty nights".  Other intervals contained within the story he probably would have counted (days aboard the ark, dove trips, etc).

But never does the Bible show him being aware of, or informed of, any of the "dates" which Moses, God's scribe, recorded for the story.  Noah relied on God to control the timeline (waters, motion of the rudderless ark), and to tell him what to do and when (enter, exit the ark).

(e)  2,553,000 Days

From the Flood to the century/millennia benchmark date* before 2011:

2-17-4990 - 1-1-2001*  =  2,553,000 days, inclusive

                       =  10^3   x   3   x   23   x   37
                       =  2,400,000  +  153,000

                       =  3700**   x   3   x   10   x   23

* 1-1-2001 Serves as a benchmark date; explained in the study Further Validation of Gregorian Dating, also on this website.
** Intervals based on 3700 days tie in to Flood dates in at least three instances.  Read more in Further Validation of Gregorian Dating.

(f)  A possible date for Creation

If we equate the "second month" / "seventeenth day" to "February 17th", a curious timeline results when choosing a possible date for Creation.

We know the Beginning was in 11013 BC.  We also know the first day was a Sunday... but which Sunday?  Consider 2-17-11013 BC (a pre-anniversary of the deluge-- also a Sunday).  This puts the creation of Man on 2-22-11013 (the Sixth Day; Friday).

Going forward 2,200,000 days gives us 7-17-4990 BC.  This then would be the seventeenth day of the seventh month (Genesis 8:4), precisely 150 days after the start of the flood.  This marked the end of when "the waters prevailed upon the earth" (Genesis 7:24) to destroy man.  Although every living thing might easily have died before this day, the waters-- expressing God's anger-- prevailed until some full measure of punishment was reached on day 150.  On this day the waters were finally abated and the ark rested (Genesis 8:3,4).  (For a timeline of Genesis Flood events, consult Assigning Dates to All Flood Events, on this website.)

A case can be built for the number 22 signifying God's wrath being satisfied.  In this case, 22 is multiplied by 100,000.  For perspective on the rarity of 100,000-day intervals, know that they occur only every 273 years.

The study Seeking an Actual Date for Creation on this website offers further details on this question.

(g)  Current teachings harmonize with Gregorian dating

Dates from 33 AD

Several currently-taught dates from Christ's life have associated weekdays.

As our proleptic Gregorian calendar counts its way backward through time, it reaches each of these important dates on the expected day-of-the-week.

                                   Weekday, proleptic
                   Associated      Gregorian calendar
    Event          weekday        used by Bible-calculator
    4- 1-33 AD     =  Fri     |    =  Fri
    Cross                     |
    4- 3-33 AD     =  Sun     |    =  Sun
    Resurrection              |
    5-22-33 AD     =  Sun     |    =  Sun
    Pentecost                 |

The 722,500 days

The accepted daycount from Cross to 5-21-2011 also agrees with the Gregorian count:

    4-1-33  -  5-21-2011  =  722500  (incl)

Was this figure arrived at through multiplication, or by walking backwards in time-- following the Gregorian leap-year rules?  (the proleptic Gregorian calendar).  It turns out that both methods will yield identical counts.

A table of Gregorian leap-year rules, with AD & BC examples, is on this website's Year Types page.

The math involved in the multiplication method:

[4-1-33 - 4-1-2011]:  1978 x 365.2422 = 722449.0716

[4-1-2011 - 5-21-2011]:               +     50

Add one to make it "inclusive":       +      1
                                      = 722500.0716
Compare this to the Gregorian count (performed here in the same steps used by the Bible-calculator), which follows a consistent set of leap-year rules:
Find quadrennial leap days...

...from 1-1-34  -  1-1-100:
   {36, 40, 44, 48, 52, 56, 60, 64, 
   68, 72, 76, 80, 84, 88, 92, 96} = 16           16

...from 1-1-100  -  1-1-2000:
   = 1900/4 = 475                           +    475

...from 1-1-2000  -  1-1-2011:
   {AD 2000, 2004, 2008} = 3                +      3
                                            =    494
Subtract the century non-leap-days:
   {AD 100, 200, 300, 400, 500, 600,
   700, 800, 900, 1000, 1100, 1200,
   1300, 1400, 1500, 1600, 1700, 
   1800, 1900, 2000} = 20                   -     20

Add back in the quadricentennial leap days:
   {AD 400, 800, 1200, 1600, 2000} = 5         +   5

Add whole years:
   34 to 2011 = 1977 
   -->  1977 x 365 = 721605                 + 721605

Add partial year, 33 AD
   [4-1-33  -  1-1-34] = 275                +    275

Add partial year, 2011
   [1-1-2011 - 5-21-2011]:                  +    140

Add 1 to form an inclusive span             +      1
                                            = 722500

Thus there is perfect agreement between these two day-counting methods:

   For the interval  [4-1-33 AD]  -  [5-21-2011]
   Astronomical multiplication:  722,500 days inclusive

   Gregorian calendar:           722,500 days inclusive

84,000 Months in 7000 years

There are 7000 years from flood to judgment.  84 Is a number tied to great tribulation in the Bible, and 7000 years adds up to 84,000 months... but only in a calendar tying twelve months to a true year of 365 (and a fraction) days. 

...What about other months-- like lunar, or even 30-day months?

The same 7000 years contain:

86,578 lunar months (complete moon cycles)

85,223 30-day months

To achieve a count of 84,000 months over 7000 years, one must count twelve months every true year. There is no scriptural basis for a twelve-month year, save for the faulty notion of a Flood-era 12 x 30 = 360 calendar; which theory is refuted above.

Neither is there any astronomical hint to count twelve months in a year.  There are no celestial markers subdividing the year into twelve.  The twelve constellations of the zodiac bear no authority, being nothing more than attempts at finding meaning out of whatever new stars happened to rise each month, by a people already using a twelve-month calendar.  The stars seen on the celestial equator each year could certainly be batched into any number of "constellations" to match any number of months.

The concept of twelve months exactly matching a true year exists only when it is artificially imposed upon the 365+1/4-day orbit, in an agreed-upon pattern of months (such as 28, 29, 30, 31, etc.; average length = ~30.5); which pattern is called a calendar.

Hidden Gregorian rhythms based on 5-months and 153-days

In our calendar, any five-month dayspan = 153 days (not incl.); provided the span does not cross from February into March.

An analysis of the pattern of 30- and 31-day months shows us why.

As described in detail above, the months' lengths, and their resulting irregular pattern were, for all purposes, accidental.  Yet embedded within Gregorian month-lengths is a five-month pattern, detectable by listing them in order, from March to February:

  Mar     May     Jul    Aug     Oct     Dec    Jan
  31      31      31     31      31      31     31    
    \    /  \    /         \    /   \   /         \
      30      30             30      30             28
      Apr     Jun            Sep     Nov            Feb
Notice the pattern of the first five months:  { 31, 30, 31, 30, 31 }.  The pattern is immediately repeated, August through December; followed by a final, partial repetition from Jan to Feb.  (Though not "30", Feb is still shorter than 31; besides, the two missing days fall inconsequentially at the end... therefore it mimics 30.)

This string of numbers, built (accidentally) upon a rhythm of five months, forms repeating patterns of five numbers, from any starting point.

In such a repeating pattern, numbers reappear at every fifth spot in the row.  We can show this by using a set of five letters:  {A, B, C, D, E}.

A  B  C  D  E     A  B  C  D  E     A  B
Select any group of five... say, the first:  A  B  C  D  E.  Shifting this "window" one place to the right loses the 'A' on the left... yet regains it on the right.  All five (A, B, C, D, E), and only these five, are always present.  This is the mechanism whereby the pattern of 153-totals is preserved:  if one group of five, in a repeating pattern of five, totals 153-- then all will, wherever the starting point.

  lose this "A"...

   A  B  C  D  E  A  B  C  D  E  A  B  C  D  E  A  B
              ...gain this "A"

M  A  M  J  J  A  S  O  N  D  J  F
 ____________   ____________   ____
31 30 31 30 31 31 30 31 30 31 31 28
_   ____________   ____________   _
31 30 31 30 31 31 30 31 30 31 31 28
____   ____________   ____________ 
31 30 31 30 31 31 30 31 30 31 31 28
_______   ____________   __________
31 30 31 30 31 31 30 31 30 31 31 28
__________   ____________   _______
31 30 31 30 31 31 30 31 30 31 31 28

M  A  M  J  J  A  S  O  N  D  J  F

Another 153-appearance lies within the daycount for ten years:

  3653  =  3500 
          + 153
           3653 days

      ten years  =  3650 + L   | L = # of leap days in a decade |
                               | L can be: |   3  |   2  |  1   |
                               |           |      |      |      |
                               | Daycount: | 3653 | 3652 | 3651 |
                               |           |      |      |      |
                               | Frequency:|  49% |  49% |  1%  |       
This appearance of 153 is ultimately due to the difference of 15.xxxx days between (350 days) and (an actual year).  When added up over ten years, the daycount = 3653, 3652, or 3651.

In these end times, with growing awareness of the Five Months and the 153 Days, it is curious to find embedded within our own calendar, patterns– of both five months, and of 153 days.

(h)  The exact placement of the 7000 years

The recently-discovered 7000-year warning in 2 Peter 3, pointing us to the End in 2011, fully agrees with prior studies, which also pointed to 2011.  This added level of inevitability heightens our sense of urgency to prepare ourselves and to warn others.

Yet this 7000-year-clue provides no time-information other than the year.

If precise dates of Flood events were to be known, then we could also have to-the-day accuracy for placing these 7000 years.

Yet not exactly where one might think.

There seems to be an automatic assumption that when the Flood started, so did the 7000-year clock.  Yet this ignores the subtle detail that in the Scripture, both clocks– 7 days, & 7000 years– began at the same moment back on 2-10-4990 BC, when God spoke in Genesis 7:4  "For yet seven days...".

We see this in 2 Peter, which attributes both destructions (flood; fire) to "the same word".

Q:  What "word" brought about the Flood?

(parts are crossed out to streamline the essential action)
2 Peter 3:5  For this they willingly are ignorant of, that by the word of God the heavens were of old, and the earth standing out of the water and in the water:  2 Peter 3:6  Whereby the world that then was, being overflowed with water, perished:

...Where "the word of God" is a reference to Genesis 7:4:
Genesis 7:4  For yet seven days, and I will cause it to rain upon the earth forty days and forty nights; and every living substance that I have made will I destroy from off the face of the earth.

2 Peter 3 then credits Genesis 7:4 ("the same word") with starting the current (7000-year) grace-period.
2 Peter 3:7  But the heavens and the earth, which are now, by the same word are kept in store, reserved unto fire against the day of judgment and perdition of ungodly men.  (emphasis added).

Therefore, as both countdowns began on 2-10-4990, the longer of the two reaches a full 7000 years on 2-10-2011.  This ancient timer, based on a count of years, need not display to-the-day accuracy; therefore the grace-period is free to expire as far as 364 days beyond the 2-10-2011 anniversary... all of which days are still within the 7000th year.

In our detailed understanding of end-time dates, the date 5-21-2011 is the modern equivalent of [2-17 / Flood-start] when the first, 7-day grace-period expired.  That the 2-17-2011 Flood-anniversary does not mark the unleashing of wrath is understandable, it being months before the required harvest-time.

We find instead a perfect 100-day pause from (Gregorian) 2-10 until the next available 2-17 (Hebrew)...  this time, at the harvest.

   2-10       2-17                     2-10           5-21
   4990 BC    4990 BC                  2011 AD        2011 AD
                                                      2-17 (Hebrew)
    |//7 days//|                         ______________ 
                                        |///100 days///|
    |////////7 0 0 0   y e a r s////////|

Further connections between 2-10 and 5-21-2011

Another numerical link between 2-10 and 5-21 involves triangular numbers.

Triangular numbers belong to a mathematical series of the form:

      {(1), (1+2), (1+2+3), (1+2+3+4), (1+2+3+4+5), ... }
   =  { 1,    3,      6,       10,         15,      ... }

These numbers are best envisioned as a set of billiard balls, racked together.  To find the next number in the series, place a new row at bottom, then add it to the previous number.  The height (the number of rows; or number of balls on any side) will describe its order of appearance in the series.  For example, the 17th triangular number is 17 rows tall (and has 17 on any side).

(The list also includes:  120 (T-15);  276 (T-23);  300 (T-24);  and 666 (T-36). )

Starting at 10-21-2011 (Destruction), and going backward 153 days, leads us to 5-21-2011 (the "latter rain" ends).

153 Is the 17th of the triangular numbers.  Its factors are: ( 9 x 17 ).

Continuing our trip backward from 10-21, we find a 253-day interval to 2-10.

253 Is the 22nd triangular number.  Its factors are: ( 11 x 23 ),  or  ( 153 + 100 ).

Here is a look at the triangular pattern, leaping backwards from 10-21-2011:

                               | Running total of days
                               | from 10-21 will be a
                               | list of triangular #s *

          Start at 10-21...         0

Go back  1 day  to 10-20           -1

another  2 days to 10-18           -3

another  3 days to 10-15           -6

another  4 days to 10-11          -10
         ...                      ...
another 16 days to  6- 7         -136

another 17 days to  5-21  <--    -153  <--
         ...                      ...
another 21 days to  3- 4         -231

another 22 days to  2-10  <--    -253  <--
* Here shown as negative numbers, while stepping back in time

2-10-2011 Also fits evenly into the 8400-days of the Great Tribulation:

    From    5-21-1988        0
    To:     9- 7-1994     2300

            4- 3-2001     4700 

            1- 1-2007     6800 (inclusive)
            2-10-2011     8300

            5-21-2011     8400

Further validation

Additional numerical- and date-evidence, in support of Gregorian dating from Creation-to-Destruction, is presented in Chapter 3, Further Validation of Gregorian Dating.

John O'Leary /

[1]  ^  "The Hebrew Calendar", Kehilas Moreshes Yaakov,

[2]  ^    "History of the Calendar", Kerry Farmer,

[3]  ^  The Lunar Motion and Data page of this website