Using Parallel Calendars

This article deals with the philosophy of constructing a timeline from the Bible. By not converting to a modern calendar the work will carry precision matched to the Bible’s natural time precision. To do this correctly means we need to carry the Bible's calendar all the way to the modern era. Then run it in parallel to modern calendars.

Work Experience

Before working on Bible projects, I worked various jobs in the tech industry. Some of those involved projects where people could die if the engineering was not done very carefully. (This is especially true in aerospace.)

People working in these situations learn to spot problems, anomalies, both in test equipment, and in their work peers. The people side is more dangerous. People can create dangerous systems by making logical mistakes that they themselves are unaware of.

One sign of a mistake, that your high school chemistry teacher may have used, is to ascribe high precision to equipment incapable of that precision. A good teacher will know the precision of all the lab equipment in the class. If a student ascribes high precision to an instrument incapable of that precision, then that student is in trouble in various possible ways. They may need more education. They may be faking the data. They might be making everything up. They might be bullying. It depends on the situation.

These tech people skills become innate. They run all the time. They transfer to every technical domain, including technical Bible studies.

Daniel's 70 Sevens, Done Bad

My first exposure to intricate, long-distance, day-accurate, time intervals in the Bible was a presentation of someone’s belief on the structure of Daniel’s seventy weeks.[1]

This presentation made a supposed linkage between certain Old Testament dates and Jesus' Crucifixion. The presentation matched the math used in the Left Behind series. I later learned the math itself was over 100 years old, used without critical examination ever since.

I had heard this presented before, but instead of a new-believer, accept-everything attitude, I looked at the presentation as I would someone presenting similar materials at my place of employment. What I saw this time startled me.

The standard, and quite popular, presentation of Daniel’s 70 weeks begins with a supposed date for the decree to rebuild Jerusalem. It then ends at the time of Jesus’ crucifixion. In order to not publish something so stupid I will not reproduce their math here.

This presentation was riddled with analytical errors at several levels. The most obvious was lack of any error analysis, analysis that should have been applied to most of the steps.

All engineering work is done under a system called error analysis. Each measured value includes an estimate of the measurement tolerance that goes with that value.

When students have numbers that come out with very high precision the instructor can usually tell that the numbers have been faked. The equipment in the room is only accurate to some known precision, and the teacher knows the equipment.

I have seen several attempts at scientific forgery in my personal history and high precision without highly precise instrumentation is a dead give-away that a forgery is underway.

The Left Behind series’ analysis of Daniel’s 70 weeks reeked of a forgery for this reason. Let me explain why below.

Once exposed to this problem, the next problem is figuring out how how to work the time line of the Bible so that we correctly understand the natural precision of the narrative. How will that precision be carried forward?

Calendar Errors

The world currently uses the Gregorian calendar. It supplanted the Julian calendar, in use in the Western world in a stable way since the year 5 AD. Before the year 46 BC the Roman Senate established the shape of the calendar by legislative fiat. In particular they inserted leap months by their own vote. This was similar to the way the US Congress today sets daylight savings time rules by legislative fiat.

The records of the Roman Senate do not pass down to us, and the exact calendar structure and exact dates has a error component that gets larger the farther back in time someone may care to measure.

That error component is something like 10 days, plus or minus, on average, for each year before 46 BC.

The Left Behind series’ 490 years of Daniel has over 450 years in this troubling time. So no date from historical events at that age should be measured more tightly that about 10 years with out further explanation.

Any attempt to claim a more accurate date from historical events at that antiquity requires an analysis as to why the value chosen is considered accurate. That is in fact the real problem.

No such analysis is ever offered by the classic analysis of Daniel’s 70 weeks.

Indeed the man who originally published that timeline was a retired head of Scotland Yard. Later fictionally portrayed as Sherlock Holmes. He was famous for having convicted more people of various crimes than any other person, ever, in that office.

He had invented the starting date for Daniel's 70 weeks, mostly out of thin air, in order forge his case for a linkage to the Crucifixion. Perhaps he forged court evidence too? Falsely condemning the innocent? I believe so.

The correct math, which we will get to, was given to Daniel by Gabriel, and points at Gabriel's own NT appearances. A topic for later.

Astronomical Observations

Note that this error analysis problem does not apply to astronomical events that have been back-calculated using modern computers because they are not actually measured against man-made ancient calendars. Understand the source of this error is poor human record keeping.

This also means that any time from a back calculated astronomical event cannot be accurately linked to many historical events because those events are dated by history with very low accuracy.

When this is done in popular media, the stories are entertainment, not science. Chronologies of ancient Egypt appear similarly flawed.

The Other Problem: Large time measurements in ancient history

The other problem, the more profound problem, with the Left Behind version of Daniel’s 70 weeks was the use of very large day-counts across this nearly 500 year period.

People don’t usually measure time with day counts even past a single month. How could long distance time measuring be done better? Especially ancient long distance time measuring?

The answer, it turns out, is simple: Leave the Bible's chronology alone, and Recast all of modern recorded time onto the Bible’s own calendar.

This answer is based in a profound idea: That the Bible started out with an accurate time keeping system, accurate enough to meaningfully record the dates of Noah’s flood. This over 7000 years ago now.

To the extent that the Bible records an accurate date, then it was day accurate on the time system used to write the Bible.

When the calendar was lost along with nearly everything else mentioned in the Bible dealing with the Exodus, the Tabernacle, Solomon’s temple and even the texts themselves, so, too was the calendar.

That accuracy cannot be recovered by back-porting the Gregorian calendar. We must work forward from that ancient, accurate, time system all the way to the modern era and then convert modern dates and events onto that ancient, inspired, time keeping system.

By leaving time on the Bible’s calendar, every ancient dated event remains in its Biblical accuracy, sometimes to individual days. Sometimes the accuracy is a month. Most commonly the accuracy is to the year.

That process of converting events dated on the Julian or Gregorian calendars will carry with it the natural tolerance that all events dated on those calendars carry. Indeed, even in this modern technical world, legacy media outlets like CNN rarely, if ever, date events accurate to the day. Why should we expect ancient off-Bible sources do to any better?

The Bible Calendar

Previous articles have dealt with the structure of the Bible’s 30 day calendar. That calendar has a 50 year, or 18,240 day periodicity, far simpler that the 400 year periodicity of the Gregorian calendar. Each day, since Adam’s first day, is simply another day on that same 30 day/month, Jubilee cycling, Bible calendar.

Nothing could be conceptually simpler.

Until the fall of Jerusalem to Nebuchadnezzar’s army, every dated event in the Bible can be accurately dated back to Adam, since it can be dated to the Bible’s internal calendar system.

That same calendar still runs today even if nobody is aware of what day it may be, on that calendar. By the end of this article series the mathematical relationship between the Bible’s 30 day calendar and the modern Gregorian calendar will be shown. With that we have a mathematically error free calendar system with which to measure modern headline events, especially predicted events.

The Steps

Getting to a working parallel Bible calendar is rather intricate. The steps will take many more articles to cover.

The result of this process allows validation of various date intervals, especially year based intervals, by simply checking to see that the year numbers in different Bible dates are off by the indicated number of years.

Long distance day numbering and counting is also possible, and not only can Daniel’s 70 weeks be better placed in history, it can be shown day accurate and at the same time include all the needed supporting error analysis.


The Bible Time website and related tools are built using the Bible’s own 30 day/month calendar. That calendar cycles every 50 years and began at the start of Adam’s 1st year. It continues to this day.

Instead of converting Biblical events to the modern Gregorian calendar and loosing all ability to apply the Bible’s own prophetic time system, the strategy followed here is to leave all events stated on the Bible’s calendar. This includes modern events that will eventually be shown to be dated on that same Bible calendar.

With all this work in place we can then track modern, predicted, headline events.

1. Daniel 9:1