Calculated or observed calendar?

Older Hebrew Calendar


Each year, some bring up calendar concerns. Some believe that a calculated Holy Day calendar is wrong and that one must be only kept based upon personal observation.  Those espousing the observed calendar often differ among themselves as to how it is to be observed.

The debate is often centered around a Jewish leader called Hillel II. He is credited for publishing the rules that the Jews use for calculating the calendar. Basically, the observed crowd claims that since Hillel was not around until the 4th century, that prior to him, the Jews always used a calendar based upon observation of the first crescent moon and did not include something called ‘postponements.’

This argument presumes, however, that Hillel II invented the calendar rules he made public. Since the calendar determining methods were guarded by the priests, we do not know that for a fact. Furthermore, some believe that this public action was necessary, because the ‘judicial body’ then known as the Sanhedrin, was a fading institution at the time, hence there was a need for public disclosure of the rules.

The calculated crowd basically says that not all Jews used an observed calendar and the Bible seemingly gave the Jews (Leviticus 23:2 and possibly the Church per Colossians 2:16-17, literal translation) some latitude in determination of the actual start date. Some believe that postponements were in place and probably used by some prior to the time of Jesus.

Back in Jesus’ time, communications were not instantaneous.  Yet, somehow Jews around the Roman Empire knew when the Day of Pentecost was as the Bible shows that they were in Jerusalem observing it on the correct day:

1 When the Day of Pentecost had fully come, they were all with one accord in one place. 2 And suddenly there came a sound from heaven, as of a rushing mighty wind, and it filled the whole house where they were sitting. 3 Then there appeared to them divided tongues, as of fire, and one sat upon each of them. 4 And they were all filled with the Holy Spirit and began to speak with other tongues, as the Spirit gave them utterance.

5 And there were dwelling in Jerusalem Jews, devout men, from every nation under heaven. 6 And when this sound occurred, the multitude came together, and were confused, because everyone heard them speak in his own language. 7 Then they were all amazed and marveled, saying to one another, “Look, are not all these who speak Galileans? 8 And how is it that we hear, each in our own language in which we were born? 9 Parthians and Medes and Elamites, those dwelling in Mesopotamia, Judea and Cappadocia, Pontus and Asia, 10 Phrygia and Pamphylia, Egypt and the parts of Libya adjoining Cyrene, visitors from Rome, both Jews and proselytes, 11 Cretans and Arabs — we hear them speaking in our own tongues the wonderful works of God.” (Acts 2:1-11)

The above is scriptural support for the idea that the calculated calendar was in place so that the Jews who came for Pentecost obviously would have to known when it was some time previous to it.  Travel was much slower then and for a message to get from Jerusalem to Rome, and then for people to get back to Rome would have taken a long time, it would not seem possible that those who visited Jerusalem from places as far away as Rome could have known when to be there, UNLESS a calculated calendar was used.  While the Roman visitors coincidentally could have been there, since Pentecost was one of the listed Holy Days to appear before God with an offering (Deuteronomy 16:16), it is likely that they knew (in advance) when it was.

It should be realized that for centuries after Jesus was resurrected, Christians who kept the Holy Days had to use some method, and since most were NOT near Jerusalem after 69 A.D., the use of a calculated calendar (which they likely knew from the Jews) was the only practical way for them to know when the Holy Days were.

Now because some rules related to the calendar were not made public prior to Hillel II (some others had been related to years with an ‘intercalated’ month), we do not know the date when they were first implemented–though some believe they existed from the time of Moses and were shown to be utilized by Ezra. It would seem logical to conclude that they were begun during the period when sacrificing was being done. One of the possible reasons I have read about for implementing them was in consideration of back-to-back High Days (before or after a weekly Sabbath) and the laborious offering rituals needed. It would not seem that postponements would have been implemented long after the Temple was destroyed with related sacrificing also ceasing by 70 A.D. If sacrifices played a role in using the postponement, then Hillel II could not have been the one to originate postponements.

According to Jewish sources. the placement of the Day of Atonement seems to be a major factor in the use of postponements. Notice the following from the Encyclopaedia Judaica:

CALENDAR (Heb. לוּחַ, lu’aḥ). The present Jewish calendar is lunisolar, the months being reckoned according to the moon and the years according to the sun. A month is the period of time between one conjunction of the moon with the sun and the next. The conjunction of the moon with the sun is the point in time at which the moon is directly between the earth and the sun (but not on the same plane) and is thus invisible. This is known as the מוֹלָד, molad (“birth,” from the root ילד). The mean synodic month (or lunation) is 29 days, 12 hours, 44 minutes, and 3⅓ seconds (793 parts (ḥalakim); in the Jewish system the hour is divided into 1,080 parts each of which is 3⅓ seconds). The solar year is 365 days, 48 minutes, and 46 seconds, which means that a solar year exceeds a lunar one (12 months) by about 11 days. The cycles of 12 lunar months must therefore be adjusted to the solar year, because although the Jewish festivals are fixed according to dates in months, they must also be in specific (agricultural) seasons of the year which depend on the tropical solar year. Without any adjustment the festivals would “wander” through the seasons and the “spring” festival (Passover), for example, would be celebrated eventually in winter, and later in summer. The required adjustment is realized by the addition of an extra month (Adar II) in each of seven out of the 19 years that constitute the small (or lunar) cycle of the moon (maḥazor katan or maḥazor ha-levanah). …

The year begins on Tishri 1, which is rarely the day of the molad, as there are four obstacles or considerations, called deḥiyyot, in fixing the first day of the month (rosh ḥodesh). Each deḥiyyah defers Rosh Ha-Shanah by a day, and combined deḥiyyot may cause a postponement of two days: (1) mainly in order to prevent the Day of Atonement (Tishri 10) from falling on Friday or Sunday, and Hoshana Rabba (the seventh day of Sukkot; Tishri 21) from falling on Saturday, but in part also serving an astronomical purpose (see below). Rosh Ha-Shanah never falls on Sunday, Wednesday, or Friday (according to the mnemonic לא אד”ו ראש known as the postponement addu – probably first vocalized iddo; cf. Ezra 8:17). (2) Entirely for an astronomical reason, if the molad is at noon or later (מוֹלָד זָקֵן or מוֹלָד יח) Rosh Ha-Shanah is delayed by one day or, if this would cause it to fall as above, two days. These two deḥiyyot, owing to the mentioned limits on the number of days in the year, entail another two. (3) The third deḥiyyah is as follows: If the molad in an “ordinary” (not leap) year falls at ג”טר”ד, that is the third day (Tuesday), at 9 hours, 204 ḥalakim, that is, 3:11 A.M. and 20 secs. – Rosh Ha-Shanah is put off two days. A postponement to Wednesday is not permitted (as in (1)), so that it is deferred to Thursday. The object is as follows: If the molad of Tishri occurs at that hour, the outcome would be a year which is one day too long…. (4) This deḥiyyah is very infrequent. It is known as בט”ו תקפ”ט אחר עבור שנה, that is when the molad of Tishri, following immediately after a leap year, occurs on the second day (Monday) at 15 hours, 589 ḥalakim, which means Monday, 9:32 A.M. and 43⅓ secs. …

While it is not unreasonable to attribute to Hillel II the fixing of the regular order of intercalations, his full share in the present fixed calendar is doubtful. … Intercalation is claimed to be evident from the figures in Ezekiel 1:1, 3:15, 4:4–6 and 8:1, with similar indications in I Kings 12:32–3 and II Chronicles 30:2–3; … The New Moon (Num. 28:11, and parallels) was determined by the phasis in the preceding evening, hence the plausibility of an early biblical record (I Sam 20:18) of its prediction for “tomorrow.”

(Calendar. Encyclopaedia Judaica. Ed. Michael Berenbaum and Fred Skolnik. Vol. 4. 2nd ed. Detroit: Macmillan Reference USA, 2007. p354-359. COPYRIGHT 2007 Keter Publishing House Ltd.|CX2587503848#354 viewed 02/28/15)

It is true that Hillel II did not come up with all the calendar calculation rules. Again, it is more likely he mainly laid them out publicly.

Psalm 81:1-5 discusses new moons, and may be a reason that the Jews believe the calculation for the new year should be based on Tishri 1. Though the sacred year, according to the Bible (Exodus 12:1-2), begins on Nisan 1, the date of that calculation seems to be based on the Tishri calculation. The fact that the Encyclopaedia Judaica ties an aspect of the calendar with Ezra 8:17 is consistent with the view that the postponements were being utilized at the time of Ezra.

Furthermore consider that Jesus kept Passover on the 14th of Nisan (also known as the month of Abib) on the Hebrew calendar after sunset on the day we now call Tuesday (see What Happened in the ‘Crucifixion Week’?). He died the next day, which is the day we commonly call Wednesday. The late Dr. Herman Hoeh taught this occurred in 31 A.D. (though 30 A.D. might be possible–as far as 30 A.D. goes, I have seen something from one supporter of that view that claimed that the Feast of Trumpets prior to it was calculated based upon a postponement).

Now, if we can have records of when the new moon was for 31 A.D., we can calculate when Passover would have been. And that information exists.

There is New Moon Data from the US Navy Observatory using the current Julian calendar and Greenwich Mean Time for the new moon in 31 A.D.:

31 ...  April 10    Noon  ( viewed 02/25/15)

Since Jerusalem is two hours ahead of Greenwich Mean Time, then the conjunction, which effectively is the start of the the actual New Moon, would have occurred at 2:00 pm on what we now call April 10th on the day of the week commonly called Tuesday (the same US Navy link states that March 27th was on a Tuesday, and from that we can calculate the days of the week for April of 31 A.D.).

If the first part or crescent of the moon could have been seen close to the time the US Navy said the conjunction for the new moon occurred, the 14th of Nisan would have began after sunset on Sunday the 22nd of April. Yet, it would not have been.

Furthermore, the human eye normally cannot see the moon in the middle of the afternoon and there are delays until enough of the moon can be seen. So it would seem that the first observable crescent should have been the next day. Thus, the first day of the month would have likely been Wednesday, April 11th, based upon a strictly observable calendar. This would have made Passover after sunset Monday, April 23rd.

Presuming Jesus was killed in 31 A.D., this eliminates the strictly observable calendar (for details on why that makes sense, check out the article The KEY To The Crucifixion Date). The beginning of the month that year would have been ‘postponed’ one day, based upon a calculated calendar. Since Jesus kept His last Passover on a Tuesday evening after sunset, this leads to the logical conclusion that Jesus kept the Passover based upon a calculated calendar (again presuming a 31 A.D. final Passover for Him). Jesus would have kept Passover after sunset on April 24th and died prior to sunset on April 25th.

And if Jesus kept the Holy Days based upon a calculated calendar, then it is reasonable to conclude that a calculated calendar existed centuries before Hillel wrote a record of it down.

Notice also the following from the late Dr. Herman Hoeh:

The Hebrew calendar tells when

Here is a chart verified by works on the "Jewish calendar" — actually God's sacred calendar — absolutely correct according to the computation preserved since the days of Moses!

Dates             Passover
A.D. 29      Saturday, April 16
A.D. 30      Wednesday, April 5
A.D. 31      Wednesday, April 25
A.D. 32      Monday, April 14
A.D. 33      Friday, April 3

To place the Passover on a Friday in A.D. 30 is to violate one of the rules of the fixed calendar — that no common year of the sacred calendar may have 356 days. Common years of 12 months may be only 353, 354 or 355 days long, a fact you can verify in the Jewish Encyclopedia.

Theologians place the Passover of A.D. 30 on Friday, April 7, 356 days after the Passover of A.D. 29. Count it for yourself! This date is two days late. The Passover in A.D. 30 was only 354 days after that of A.D. 29.

The 14th of the month Nisan could have occurred on Wednesday in A.D. 30, as well as in A.D. 31. Thus, if you want to believe that the crucifixion was in A.D. 30 — which it was not — you would still have to admit that Friday could not be the day of the crucifixion!

For the year A.D. 31 a few references, unacquainted with the rules of the Hebrew calendar, mistakenly give the Passover, Nisan 14, as Monday, March 26. But this is one month too early. The year A.D. 30-31 was intercalary — that is, it had 13 months — thus placing the Passover 30 days later in A.D. 31, and on a Wednesday. (Hoeh H. The Crucifixion Was Not on Friday, Part Two. Good News magazine, March 1984)

Since Jesus kept Passover on Tuesday night (the day starts the evening prior on the Hebrew calendar, hence a Wednesday calendar date means a Tuesday evening obvserance, since Passover is observed in the evening) and died Wednesday afternoon, it appears that He was keeping a calculated calendar with postponements.

Understand that many of the children of Israel were dispersed from Jerusalem for centuries. This of course separated them from accurate Jerusalem observations. Since all wanted to keep the right day, a calculated calendar was a logical solution to this (though odd solutions, such as observing the holy days for two days, were used by many, as some do today).

On sufficiently cloudy evenings/nights, it is not possible to observe the first appearance of the new moon through observation.  Thousands of years ago, they would not have had a way to observe the start of the new moon every month.

There are many reasons why a calculated calendar makes sense. Consider:
  1. Modern communication methods did not exist thousands of years ago.
  2. Jesus endorsed the basic Jewish calendar (cf. Matthew 23:1-3).
  3. Jesus, who did not sin (Hebrews 4:15), seemingly observed a calculated calendar (cf. Luke 22:8-22, etc.).
  4. Throughout history God’s people not near Jerusalem basically had to rely on some type of a calculated calendar.
  5. Weather and other factors made a strictly observational calendar impossible for use every month.
  6. A strictly observational calendar results in people keeping Holy Days sometimes weeks differently, depending up where they are physically located.
  7. God is not the author of confusion (1 Corinthians 14:33).

There is more information that could be provided on each of the above points, but even though I plan to research more on this in the future,

Back to home page.

Some items of possibly related interest may include:

The KEY To The Crucifixion Date This is an article by Paul Kroll pointing to 31 A.D. by way of Daniel 9 and Artaxerxes' decree in Ezra 7.
Is There “An Annual Worship Calendar” In the Bible? This paper provides a biblical and historical critique of several articles, including one by the Tkach WCG which states that this should be a local decision. What do the Holy Days mean? Also you can click here for the calendar of Holy Days.
What are Postponements? This was written by the late evangelist Raymond McNair and explains a lot about postponements and calculations.
Hebrew Calendar and “Postponements” This late John Ogywn writing explains why the most faithful in the Church of God use the calendar that we do and answers such questions as “Did Jesus Observe the Postponements?”
Holy Day Calendar This is a listing of the biblical holy days through 2024, with their Roman calendar dates. They are really hard to observe if you do not know when they occur :) In the Spanish/Español/Castellano language: Calendario de los Días Santos. In Mandarin Chinese: 何日是神的圣日? 这里是一份神的圣日日历从2013年至2024年。.
What Happened in the ‘Crucifixion Week’? How long are three days and three nights? Was Palm Sunday on a Saturday? Did Jesus die on “Good Friday”? Was the resurrection on Sunday? Do you really know? Who determined the date of Easter? (Here is a related link in Spanish/español: ¿Murió Jesús un día miércoles o un viernes?)
Passover and the Early Church Did the early Christians observe Passover? What did Jesus and Paul teach? Why did Jesus die for our sins?
Melito’s Homily on the Passover This is one of the earliest Christian writings about the Passover. This also includes what Apollinaris wrote on the Passover as well. Here is a related sermon, also titled Melito’s Homily on the Passover.
TPM: Passover on the 14th or 15th? While the real COG observes Passover on the 14th, some observe it on the 15th. Why is the 14th correct? A related sermon is titled Is Passover on the 14th or 15th for Christians?
The Night to Be Observed What is the night to be much observed? When is it? Why do Jews keep Passover twice and emphasize the wrong date? A related video is available and is titled The Night to Be Much Observed.
Should Christians Keep the Days of Unleavened Bread? Do they have any use or meaning now? What is leaven? This article supplies some biblical answers. Here is a YouTube video intended to be viewed for the first day of unleavened bread: Christians and the Days of Unleavened Bread.
Should You Observe God’s Holy Days or Demonic Holidays? This is a free pdf booklet explaining what the Bible and history teach about God’s Holy Days and popular holidays.
The History of Early Christianity Are you aware that what most people believe is not what truly happened to the true Christian church? Do you know where the early church was based? Do you know what were the doctrines of the early church? Is your faith really based upon the truth or compromise?