page is dedicated to the study of changes in the calendar.

Its aims are to promote thinking about future calendar reform,
and to collect information on all aspects of historical reforms.

James Morton McCarty

Welcome to the Home Page for
Calendar Reform

Standing Proposals | Historical Reforms | Future of Calendar Reform
Calendar Links | Mail

Look up your birthday on
The ISO Week Date Calendar


The dominant conceptual scheme for civil time-keeping at present is the Gregorian Calendar: a 400-year-old modification of a 2000-year-old scheme known as the Julian Calendar. First instituted on Papal authority, the Gregorian Calendar's primary purpose was to restore a continuity of time-keeping with an Early Christian era some twelve centuries prior.

Time-keeping and scheduling in our present, post-industrial, information-age society thus rely on an anachronistic scheme serving the interests of men in a pre-scientific, theocratic society, with a feudal economy.

The invention of mechanical clocks made it possible to divide every day into twenty-four equal time-segments. The day is therefore easily divisible into halves, thirds and quarters, as is each of its twenty-four hours. The practical advantage of these regular divisions over the variable divisons of daylight, from dawn to noon to sunset, is obvious.

In contrast, the Gregorian Calendar's strict adherence to the solar cycle produces an expiring calendar every year. This requires continual schedule-revisions for many important activities, such as education. It also precludes regular divisions within the year necessary for accurate statistical comparisons. Half-years have an equal number of days only in leap-years; the year never divides evenly into quarters; the months are irregular; and neither the year nor the months can be divided regularly into weeks.

It doesn't have to be this way.

Standing Proposals for Calendar Reform

Reform seemed imminent in the earlier decades of the 20th century, as mechanisms for world-wide social progress developed with the League of Nations and subsequently in the United Nations.

Two reform proposals then attracted the most attention. These seemed to offer the best solutions to contemporary time-keeping and scheduling problems caused by the irregularities of the Gregorian Calendar. Each recommended a perennial calendar involving the use of so-called "blank days." The blank day concept was suggested originally, perhaps, by Rev. Hugh Jones, an American colonist from Maryland writing in 1745 under the pseudonym of Hirossa Ap-Iccim. The idea was later popularlized by an Italian priest, Abb Marco Mastrofini, in 1834.

These proposals were a 12-month scheme with identical quarters, known as "The World Calendar," and a 13-month scheme with identical months: "The International Fixed Calendar." The latter originated in the mid-19th century as "The Positivist Calendar" of Auguste Comte, and was also named for its prominent promoters in this century: "The Cotsworth Plan" and "The Eastman Plan."


A History of Calendar Reforms

The present civil calendar followed by most of the world has its origins in the early Roman civilization. Julius Caesar reformed the Roman Calendar in 46 BC, simplifying the periodic calendar correction by adding an extra day to February every four years. Our month of July, formerly "Quintilis," was therefore named in honor of Julius.

Because the Julian leap-year rule was not followed correctly at first, Caesar Augustus introduced a subsequent calendar correction around 8 BC. Our month of August, formerly "Sextilis," was accordingly named in his honor.

With the lengths of the year and months established, the Julian Calendar still preserved the Roman Kalends, Nones and Ides for the divisions within the months. Emperor Constantine then reformed the calendar in the 4th century, by introducing the seven-day week, probably modeled on the Christian sabbatical cycle.

But the Julian calendar year eventually proved to be slightly longer than the solar year. By the 16th century, the beginning of spring fell in early March. Pope Gregory XIII, acting on the advice of Christopher Clavius, therefore excised 10 days from the calendar by shortening October 1582, and he revised the leap-year rule: No leap years in centesimal years (e.g. 1700, 1800, 1900), except those divisible by 400 (e.g. 2000, 2400, 2800).

Most European nations adopted the Papal reform relatively quickly, with the exception of Britain and its Colonies, which held out until 1752. At that time, 11 days had to be excised in order to bring the British calendar into sync with the rest of Europe.

The French adopted a "Revolutionary Calendar" for about a dozen years in the nineteenth century, until Napoleon reestablished the Gregorian Calendar in 1806. The "Republican Calendar" was later reinstituted in Paris for several months in 1871.

Russia and the Soviet Union converted to the Gregorian Calendar after the Revolution, in 1918.

The Eastern Orthodox Churches continued observing the Julian Calendar until 1923, at which time some, but not all, skipped the first 13 days in October, and introduced a "Revised Julian Calendar" with a unique variation on the leap-year rule. This has caused a schism between New Calendarists and Old Calendarists. The problem remains unresolved.


The Future of Calendar Reform

Let us seriously consider the prospect that calendar reform is dead. Calendar reform as we know it is someone's imposing a new or even only slightly revised calendar upon everyone else, whether they want it or not. This happens always in the context of an institution. Reform is an institutional phenomenon, flowing always from the top down. The head of the institution, whether it be a Caesar, a Pope, or a Parliament, determines that its calendar has a problem, and implements a solution. Everyone subject to the institution's authority either accepts the reform, or breaks away and continues following the old calendar.

Top-down calendar reform is not going to happen, because nothing is seriously wrong with the Gregorian calendar. At least there are no problems serious enough to justify reform. At the present stage of technological advancement, the benefits of any significant reform will never outweigh the costs. The Y2K problem, which required only a small software correction, gave us a glimpse of the technological costs of calendar reform in the modern era. The modern political costs of reform can hardly be estimated. Status quo is far more prudent than calendar reform for political leaders in democratic societies.

Calendar reform as we know it may be dead. But there is no reason to think calendar change cannot happen. It is still possible to change the calendar of institutions from the bottom up. It takes time, however; at least several generations. The best strategy for this change is a Trojan horse. A new system for recording dates can be introduced—a system similar enough to the Gregorian calendar that it need not replace it, so the two dating systems can operate together. Provided the new system offers advantages lacking in the Gregorian system, lower-level managers who make institutions work will prefer it. Generations after its introduction we can expect to find almost everyone specifying their birthdays, anniversaries and paydays in the new date format. At that point, the new dating system will have replaced the old "church calendar."

For more, see Weekdate, the calendar Trojan horse.


Calendar Links


Mail to: Rick McCarty