Bill and Karen Bishop’s book The Biblical Calendar Then and Now is bound to stir up controversy.
However, the same could be said of most literary works that challenge preconceptions and personal prejudices. If you’re like me, you are reluctant to dismiss a topic simply because it may make others feel uncomfortable. The goal is not to upset or to trigger others, but to motivate all of us to dig a little deeper and pray a bit harder in the pursuit of Scriptural truths. The late Walter Martin understood that, in the pursuit of truth, many would be labeled controversial.

This brings us to the topic of the Biblical calendar. Never has one word — calendar — stirred up so many passions amongst followers of Yeshua and worshippers of the Almighty. Mention the calendar and mayhem and confusion will inevitably follow.
The Great Calendar Divide
The only calendar most believers were exposed to in church included seasonal observances that were never a part of Torah-observant ancient Hebraic culture. These traditional religious expressions of faith may have involved participating in family Christmas or Easter gatherings.
As believers, we look for ways to express and fight for the faith that was once and for all delivered to the saints.
Beloved, while I was making every effort to write you about our common salvation, I felt the necessity to write to you appealing that you contend earnestly for the faith that was once for all time handed down to the saints.
Jude 1:3 NASB
Those who are new to the Torah inevitably find themselves torn between sincerely desiring to observe Yahuah’s feast days and appointed times and maintaining healthy family relationships. Confusion over how to express this faith in a post-temple priesthood era only adds to the frustration.
There are other challenges believers face when trying to find “the correct” calendar to follow:
- A lack of a clear Biblical calendar methodology
- Ignorance of historical events that impacted calendar methodology
- Rejection of extra-biblical writings that may shed light on calendar construction methodology
- Silence from the pulpit regarding Yah’s calendar and its required Sabbaths, Feasts, and appointed times
- Lack of understanding of how the calendar we follow is tied to our Covenant duties and responsibilities

Enter Bill and Karen Bishop and their book The Biblical Calendar Then and Now.
The authors humbly submit that their work is a way for the reader to challenge personal assumptions and stretch their understanding concerning how the calendar is divinely constructed. While not intended to be a theological dissertation on the calendar, the authors’ intention is clear — “to provide a practicable body of evidence that will spur further revelation through constructive dialogue, study, and debate on this topic among sincere believers of the Torah.”
The tone of the book is respectful and substantive. The chapters are designed to answer most of the questions they have encountered over the years. The writing is very straightforward, and the reader is encouraged to invest the time necessary to do their own research. The approach is not that of calendar “evangelists” whose motive is to sway you to their way of thinking. Their conversational writing style draws you in and logically walks you through the justifications given for various calendar-keeping methodologies.
The Biblical Calendar Book Review Synopsis
The book begins by helping the reader understand four main categories of Torah-based calendars and the methodology behind their determinations:
- Luni-Solar
- Astronomical Conjunction
- The Sighting Method
- The Hillel Method
The GWDF community will notice I did not mention the Zadokite calendar in this list. Hold on, it’s coming.
Chapter 1 of the book helps the reader understand how these different calendars are formulated. In the second chapter, the authors present a calendar “consideration” that has been hiding in plain sight for years. They point out in appropriate detail how the sun and harvest seasons (working together) help determine the timing of the feasts.
The Luminaries and Their Cycles
Most English-speaking followers of Yeshua lack a functional knowledge of Hebrew. When we read through the Psalms and Old Testament literature, words like “new moons” or “seasons” distort our understanding of what is written. Etymology matters.
In chapter 3, the authors delve into the Hebraic intent of certain words; even examining aspects of the Hebrew Aleph-Bet. Words and definitions play a key role in understanding calendar formulations that involve the luminaries that were created on Day 4. The four seasonal transitions (spring, summer, autumn, winter) are explained in connection with the annual equinoxes and solstices.
Since all calendars require periodic adjustments, the need for intercalation is also explained and discussed in detail.
Historical Context + Ancient Writings
According to the writers, the Babylonian exile and the corruption of the Levitical priesthood are also factors in how the Biblical calendar was corrupted. They encourage readers to do a deep dive into the history surrounding the Sadducees, Pharisees, the Hasmonean Dynasty, and the Dead Sea Scrolls. According to the authors:
Though the Sadducees and the Pharisees did not agree in many respects, these two groups managed to cooperate with one another to run the Temple in their day…The calendar decisions they made then would have been based on lunar criteria, and loosely hinged to the evolving calendar we know as the Jewish Hillel calendar today. However, the Dead Sea Scrolls and encyclopedic research confirm that some sectarian groups observed a calendar other than the one sanctioned by the Sanhedrin.
The Zadokite Calendar
In Chapter 10, sufficient attention is paid to the Zadokite solar calendar. The authors confess that they initially tried to find reasons to disqualify this version of the Biblical calendar but couldn’t. Biblical Scripture is the filter through which they base their conclusions.
These observations regarding this calendar are made in this chapter of the book :
- The “festival nature” of the equinox and solstice seasonal markers
- The Zadokite year always makes a complete circuit
- The Biblical New Year always begins in Spring
- The year will always begin on Day 4 (Wednesday) of creation
- A year = 364 days/52 weeks of 7 days each
- There is never a 13th month added (for intercalation)
Make Your Own Calendar
Chapter 21 ties everything together by revisiting reasons why a lunar-based reckoning did not make sense for a people (Hebrews) whose lifestyles were agrarian-centric. Again, the authors leave the final decision as to which calendar to follow up to the reader.
However, those who would like to “test” the Zadokite calendar are given the tools to do so in the appendices section of the book. They provide the formulae and templates, data, and schemata necessary to make your own Zadokite calendar.
Those who are serious about meeting with their Creator on the appointed days he ordained should consider purchasing this book. A link to the Bishop’s website — Returning to the Garden — is posted below.
Book Ratings:
- Research — 5/5
- Writing — 5/5
- Support Materials — 5/5
The Biblical Calendar Then and Now is 96 pages long. It is very easy to read and comprehend. There is bonus material in the appendices section at the end of the book. Those who want to put into practice what they have learned about the Zadokite solar calendar can use the templates, data, and schemata to chart their own calendar year!
Website: Returning to the Garden
Purchase the book on Amazon
Brenda Ross is a co-author of the book, "The Gospel Worth Dying For." She is a former major market radio and television broadcaster who has served as Single’s Ministry Director at one of Houston’s Memorial Drive-area churches, a Jews for Jesus staff volunteer, and participated in mission outreach activities in Costa Rica, Mexico, and China. Urban mission experience includes volunteer work for Habitat for Humanity and catering to the homeless in San Francisco’s Tenderloin district.
Oh I look forward to reading this!
Before I buy this book, just curious does it go into the full moon maybe being the real “new moon” or start to each month?
Emerald,
In chapter 3 of the book the authors explain on page 7: “The wording “new moon” or “new moons” is used 20 times in our KJV Old Testament. The term that is translated as “new moon” is always the same Hebrew word: “chodesh.” Likewise, without exception, the plural (“new moons”) is always the plural form of “chodesh” (“chodeshim”)…Notably, Strong’s illustrates here that the word “chodesh” does not always include the lunar aspect. It can simply mean month, monthly, or the 1st day of the month.”
If you require a more detailed explanation, I suggest you contact the authors directly. Their website is: https://www.returningtothegarden.com