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Calendar Systems Dating Bible Events

This article is written (Oct 2013) to supplement our upcoming “The Bible in History – Methods and Challenges of Establishing a Biblical Timeline” series.

Navigation Notes:  We've split this series of articles into multiple pages.  You may click on the “[TOC]” links within the pages to return to the Table of Contents.

Table of Contents


Almost all of us in varying degrees, order our lives according to time and dates.  In our global society today, we encounter different time zones and may even cross the International Date Line, but the basic units for time and dates are universally consistent.  The International System of Units for time is based on the second, and the units of minutes, hours, days and weeks are acceptable in both the English and metric systems; although the divisors may differ, but this doesn’t concern us for our purposes here.  Similarly, the Gregorian calendar has achieved an almost universal acceptance in the various general, commercial and scientific realms.

Unfortunately for Bible historians, a common dating structure was rarely available prior to the Middle Ages.  In fact, one of the first challenges that we encounter when attempting to date biblical events is the is the diverse and changing calendar (or dating method) systems that were in use.  During biblical times, different nations, regions or people groups often had their own calendar.  Finally, to complicate matters even further, nations would sometimes opt to change their established or “official” calendar at a certain point.  Sometimes this change was voluntary, such as when more accurate astronomical data became available.  On other occasions, a nation or people group might be forced to change by another conquering nation.  Consequently, when utilizing records from multiple nations, numerous conversions might be required to establish the date of a single event with respect to our modern calendar.

Thus, we can readily see that a basic working knowledge of various calendar systems within their historical context is a pre-requisite for gaining a fuller understanding of the Bible dating methods.  The purpose and goal for this article is to provide this knowledge.

In part 1, we'll examine the types of calendars and their components.  In part 2, we’ll explore the development of various calendar systems within the political and historical context of the major nations during Biblical times and the early church period.  In part 3, we'll look at the origin of our modern BC-AD (Anno Domini) dating system.  In part 4, we'll chronicle the adoption of the dating system in the midst of the Roman church-state power struggles between the papacy and the crown.  Finally in part 5, we’ll focus on the historical events that led to the development and adoption of our modern Gregorian calendar system.  We then close with a few words about the methods and process of converting dates between different calendar systems, and with some final thoughts on the Anno Domini system as it relates to the Christian era.

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The following works were consulted when doing research for this article:

New Mexico State Univ Astronomy Dept  -

Gen calendar info -

1906 Jewish Encyclopedia, Funk and Wagnalls (Public Domain)

“The Western Calendar and Calendar Reforms” in the Encyclopedia Brittanica

History of the Christian Church, Volume III: Nicene and Post-Nicene Christianity, AD 311-600 - Schaff, Philip (1819-1893)

Eusebius Pamphilus: Church History (from Nicene and Post-Nicene Fathers of the Christian Church, Philip Schaff, ed)

NASA Lunar Eclipse Page -

Exploring Church History; Vos, Howard; Thomas Nelson Publishers, Nashville, 1996 (Nelson's Christian Cornerstone Series)

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