Our Calendar: The Julian calendar and its errors. How corrected by the Gregorian. Rules for finding the dominical letter, and the day of the week of any event from the days of Julius Caesar 46 B.C. to the year of our Lord four thousand

In Short

This work is an instructional and historical treatise on chronometry, examining how human civilizations have measured time from antiquity to the far future. Rev. George Nichols Packer details the structural flaws of the ancient Egyptian, early Roman, and Julian calendars, explaining how the Gregorian reform corrected a accumulating ten-day drift. Through mathematical formulas, dominical letters, and reference charts, Packer provides practical methods for calculating the exact day of the week for any event between 46 B.C. and A.D. 4000. It remains a fascinating historical artifact showing one late-nineteenth-century author's dedication to organizing civil and sacred time.

The Story

The narrative opens with an examination of early human efforts to reconcile civil timekeeping with the orbital realities of the solar system. Packer explains that early systems, such as the Egyptian vague year of 365 days, lacked proper intercalation, causing the start of the year to wander through every season over a 1460-year cycle. The early Roman system similarly struggled, relying on lunar months and chaotic intercalations controlled by civic pontiffs who altered month lengths for political gain or personal favoritism. By the time Julius Caesar took power, the civil calendar drifted three full months behind the solar seasons, prompting the creation of the Julian calendar with its leap-year rule.

Packer then moves into the fundamental flaw of the Julian calendar: its slight overestimation of the solar year's true length. Over centuries, an uncorrected surplus of roughly eleven minutes per year slowly pushed astronomical events out of alignment with civil dates. By the sixteenth century, the vernal equinox had drifted ten days off its original placement during the Council of Nice in A.D. 325. Packer describes how Pope Gregory XIII reformed the system in October 1582 by expunging ten days from the calendar—turning the day after October 4 directly into October 15—and modifying leap-year rules for century mark years.

From historical exposition, the text transitions into an operational manual for chronological computation. Packer presents systems using "dominical letters"—a sequence from A to G assigned to the days of the year—to calculate the exact day of the week for any historical or future date. He illustrates how leap years require two dominical letters because the extra day shifts the calendar sequence back by two places. Moving beyond civil time, Packer details the Metonic nineteen-year lunar cycle and the calculation of epacts used to fix ecclesiastical observances, particularly the complex rules determining the date of Easter Sunday. He extends his survey to religious observances, explaining the Hebrew calendar’s intercalary months, Christian holy days like Passion Week, and folk customs such as All-Souls' Day.

The book closes by demonstrating the real-world impact of calendar calculation on historical memory. Packer highlights a contemporary controversy surrounding the 1892 quadricentennial of Christopher Columbus's voyage, showing how an incorrect date was initially chosen by national committees before mathematical correction shifted the official observance from October 12 to October 21.

How It Unfolds

The mechanics of solar time The book opens by laying out the physical realities of the Earth's orbit and explaining why ancient calendars continuously failed to align civil years with natural seasons. Packer details the erratic 1460-year cycle of the ancient Egyptian calendar and the political corruption that distorted early Roman timekeeping.

Caesar and the Julian reform Packer explains how Julius Caesar established the Julian calendar in 46 B.C., introducing a consistent four-year leap-year intercalation to correct a three-month seasonal drift. He shows how this system functioned well for centuries but contained a tiny mathematical error that slowly accumulated over time.

The Gregorian correction The narrative examines the 1582 papal edict of Gregory XIII, which dropped ten days from October to realign the vernal equinox with the Council of Nice's baseline. Packer explains the new rule suppressing leap years in century years not divisible by 400 to prevent future drift.

Rules of the dominical letter Packer introduces a system using the letters A through G to compute days of the week across thousands of years. He walks step-by-step through mathematical division formulas and remainder operations, showing how to calculate dates starting from the beginning of the Christian era through A.D. 4000.

Mapping sacred and lunar cycles The focus shifts to the Metonic nineteen-year lunar cycle, epacts, and ecclesiastical calculations. Packer details the rules formulated by the Council of Nice to establish Easter Sunday and provides detailed tables mapping the Hebrew calendar to modern civil dates.

Historical applications and corrections The text concludes with detailed comparative tables of holy days, traditional calendar customs, and an appendix showing how mathematical accuracy resolved the historical timing of Columbus Day in 1892.

The People

Because this text is a work of non-fiction chronometry, its key figures are historical reformers, religious leaders, and researchers who shaped or organized timekeeping.

• Julius Caesar: The Roman statesman who sought to end the chaos of the early Roman calendar. Facing a three-month gap between the civil year and natural seasons, he instituted the Julian calendar in 46 B.C. with a standard 365-day year and a quadrennial leap year.
• Pope Gregory XIII: The sixteenth-century pontiff who wanted to restore the vernal equinox to its A.D. 325 position to fix the calculation of Easter. He issued an edict striking ten days from October 1582 and established the modern leap-year rule for century years.
• Dionysius Exiguus: A sixth-century monk who sought to establish a unified timeline centered on the incarnation of Jesus Christ. He devised the Christian era dating system, viewing Christ as the turning point of human history, though his estimates placed the era's start several years late.
• Rev. George Nichols Packer: The author himself, an invalid Methodist minister living in poverty who sought mental relief in calendar mathematics. Driven by a desire to simplify chronological computation, he successfully campaigned to correct the national 1892 Columbus quadricentennial date from October 12 to October 21.

In Its Own Voice

"Friday, the 5th, and Friday, the 15th, was one and the same day; there was no interval, nothing ever occurred, there was no time for anything to occur; the edict of the Pope decided it; he said the 5th should be called the 15th, and it was so."

Packer emphasizes that the ten omitted days in October 1582 were an administrative adjustment rather than lost time.

"It was a great thought of the little monk (whether so called from his humility or littleness of stature is unknown), to view Christ as the turning point of the ages, and to introduce this view into chronology."

The author reflects on the lasting historical impact of Dionysius Exiguus's calendar design.

What It's Really About

Underneath its dense tables and mathematical steps, the book is about humanity's effort to impose order on physical reality. The movement of the Earth around the Sun does not conform to clean whole numbers, leaving a fractional remainder that continuously disrupts human attempts at orderly timekeeping. Packer presents the calendar as a grand bridge connecting astronomy, civil law, and spiritual devotion. By detailing how empires, popes, and scholars managed this small fractional error across millennia, the author shows that tracking time requires continuous reconciliation between cosmic movements and human conventions.

Why Read It Today

Our Calendar offers a fascinating window into late-nineteenth-century popular science and chronological study. It appeals to readers curious about the history of mathematics, classical astronomy, or the hidden mechanics behind modern schedules. Reading it reveals how much unseen labor went into creating the standardized dates taken for granted today.

The book is clear and methodical, written with an earnest desire to make complex mathematical systems easy to understand for everyday readers. While it includes dense numerical tables, archaic Roman date notations, and technical discussions of epacts, Packer’s step-by-step arithmetic guides the reader carefully through each process. His personal background—creating these formulas while recovering from severe illness—adds a grounded human touch to an otherwise technical subject. Readers will come away with a permanent appreciation for why leap years exist, how Easter is set, and how humanity learned to synchronize its clocks with the cosmos.