A 2025-Year-Old Misconception: The Gregorian Calendar Has No Connection to Prophet Isa (Jesus, Peace Be Upon Him)

It is commonly assumed that the start of the Gregorian calendar is directly tied to the birth of Prophet Isa (Jesus, peace be upon him), and that New Year’s Day marks his birth. However, the reality is that the Gregorian calendar, used globally today, is based on reforms introduced by Pope Gregory XIII in the 16th century, not on the actual birth date of Prophet Isa.

Discrepancies in the Birth Year of Prophet Isa

According to Dr. Hanna Gress Khodary, a Coptic scholar and author of the Encyclopedia of Christian Thought History, there is considerable disagreement regarding the year and day of Prophet Isa’s birth. Historical records suggest his birth occurred sometime between 5 BCE and 2 CE. Others speculate it was between 7 BCE and 3 CE. These discrepancies highlight the uncertainty surrounding the timeline.

The author explains that the current Gregorian calendar does not accurately reflect the actual birth year of Prophet Isa. This is due to inaccuracies in the calculations made by Dionysius Exiguus, a monk in the 6th century, who developed this calendar based on the Roman calendar. The Roman calendar itself began in 745 BCE, marking the founding of Rome. Dionysius assumed that the event of the “Incarnation,” according to Christian belief, took place in what he designated as Year 1. Thus, he marked this as the dividing line between the “old” and “new” eras. However, based on historical analysis, it is estimated that Prophet Isa’s birth occurred around 4 BCE or 5 BCE.

Errors in the Gregorian Calendar

Interestingly, historians have identified a four-year discrepancy in the Gregorian calendar. For instance, while we currently consider this year to be 2024, it should technically be 2028 based on the calculations of Prophet Isa’s birth. This miscalculation originated from errors made by historians during the 7th century. Once discovered, no corrections were made to avoid disrupting established historical records.

Additionally, it is worth noting that the months of the Gregorian calendar were originally arranged differently. For instance, the year once began in March, during spring. Later, January became the first month of the year, following the assumed birth of Prophet Isa. The remnants of the original arrangement can still be observed in the names of certain months: September (meaning “seventh”), October (“eighth”), November (“ninth”), and December (“tenth”)—names that no longer align with their current positions in the calendar.

A Clarification for Awareness

While this article aims to shed light on historical inaccuracies in the Gregorian calendar, it is not intended to offend any faith or belief. Instead, it serves as an opportunity for reflection and understanding of how historical events and beliefs have shaped today’s calendar.

For Muslims, it is crucial to approach such discussions with wisdom and respect, upholding the principles of dialogue and coexistence while preserving the essence of truth. Prophet Isa (peace be upon him) holds a revered position in Islam as one of Allah’s messengers, and this article underscores the importance of accurate knowledge regarding historical and religious events.