The Leaping Saint and Other Fascinating Facts About Leap Year

By Sean M. Wright

Every fourth year, someone is elected President of the United States. Every fourth year, since 1896 save during times of war, the world has celebrated an Olympiad. And, every fourth year, the month of February is one day longer, reminding us that every fourth year is a Leap Year — usually. 

Leap Year is a necessity. The earth we live on revolves around the sun in about 365.242189 days —  or, to be precise, a total of 365 days, 5 hours, 48 minutes and 45 seconds.

From ancient times, several Mediterranean civilizations kept a 355-day year. Every few years a leap-month — known as an intercalary or epagomenal month — was inserted to bring the year back into line with the vernal and autumnal equinoxes. On the other hand, the 360-day-long Egyptian year ended with either five or six added days, which did the same job. This system survives in the liturgical calendar of the Coptic (Egyptian) Church.

Having taken over leadership of the Roman Republic, Julius Caesar called for reforming the calendar. He ordered the astronomer Sosigenes to work on the project.

Sosigenes decided on a 365-day year. Aware of the yearly addition of six hours, and knowing that four times six equals twenty-four, Sosigenes came up with adding an extra day every four years to February, which was the last month in the Roman calendar (March being the first month). Thus, in 46 B.C., the Julian Calendar was put into effect and Leap Day followed.

Sosigenes, however, blundered. As noted above, the extra time is 11 minutes and 14 seconds short of six hours, resulting in a new day every 128 years. The error became obvious, but the Romans were loath to monkey around with the calendar authorized by the now-divine Julius, who even had the fifth month of the year — July — renamed in his honor. 

In any event, the Catholic Church was founded by Christ, the real God incarnate. His resurrection became the focal point of worship; its yearly anniversary observed by the entire the Church. The calendar’s problem persisted and reform was advised, if not strongly pressed upon, the attention of the pope by one ecumenical council after another, including, in its final session, by the Council of Trent in 1563.

By the 16th century, the Julian Calendar was ten days out of alignment with the seasons. The vernal equinox now fell on March 11, and the autumnal on Sept. 11. The shortest day was Dec. 11, and the longest was June 11, the feast of St. Barnabas, whence came the old rhyme:

“Barnaby bright, the longest day and the shortest night.”

Worse, the error was causing havoc with the celebration of Easter, prescribed by the First Council of Nicæa (325) as occurring on the first Sunday following the first full moon of Spring.

In the Holy Year 1575, Pope Gregory XIII (1572-1585) called together a commission to consider the calendar devised by Aloysius (Luigi) Lilius, a brilliant Italian physician, astronomer, philosopher and chronologist. Lilius died in 1576 but Christopher Clavius, a German Jesuit priest, mathematician and astronomer, and Pedro Chacón, a Spanish priest, professor of Greek, theologian, historian and mathematician, labored to perfect Lilius’ work. What is now known as the Gregorian calendar was put into provisional use in most Catholic countries in 1578.

Issuing the papal bull “Inter Gravissimas” (Of the Gravest Concern) on Feb. 24, 1582, Pope Gregory dropped ten days (Thursday, Oct. 4 to Friday, Oct. 15, 1582). He ordered clergy to use the new calendar liturgically, while urging all Catholic sovereigns to adopt the same for the civil year.

Protestant countries, many calling the new calendar the work of Antichrist, took another 200-300 years to effect that change. The Orthodox Church, citing lack of a directive by an Ecumenical Council, continues using the Julian Calendar, now 13 days behind.

The genius of the Gregorian calendar is to drop Leap Year in all century years not divisible by 400. Therefore, 1700, 1800 and 1900 had 365 days, while 1600 and 2000 had 366 days. So well did this trick solve the problem of those pesky 5 hours, 48 minutes and 45 seconds that 35 centuries will pass before this error results in a single extra day, since the length of the Gregorian year exceeds the true astronomical year by 26 seconds.

Leap Year Liturgy — Matthias the Leaping Saint!

Although Pope Gregory’s new calendar solved the seasonal problems with the year, it caused a liturgical problem — what to do on Leap Year Day? Long before, the Orthodox Church had assigned Feb. 29 to St. Cassian, celebrated every fourth year.

The Catholic Church did not want a saint’s day occurring once every four years. It borrowed the Julian calendar’s method of counting days by Calends, Nones and Ides. The Roman Leap Year Day was the 24th of February. The 24th day was doubled on the 25th day, the sixth before the Calends (or first) of March.

This additional day was called “double-sixth-day.”  The Church had designated Feb. 24 as the feast of St. Matthias, the disciple chosen to fill the place of Judas among the apostles (Acts 1:15-26).  In Leap Year, the 24th was simply repeated on the 25th, and St. Matthias was again commemorated, being said to “leap” to the next day, allowing the saints’ days following to remain, ending the month as usual.

This tradition was preserved in Catholic liturgy until 1969, when St. Matthias’ fourth-yearly leap came to an end. His feast was moved to May 14 so it could be celebrated outside of Lent and closer to the Solemnity of the Ascension.

Today, four of the many saints assigned for commemoration on Feb. 28 are repeated on the 29th: St. Antonia of Florence, St. Augustus Chapdelaine, Pope St. Hilary, St. Oswald of Worcester. However, these saints are no longer entered in the Universal Liturgical Calendar.

(Sean M. Wright, MA, award-winning journalist, Emmy-nominated television writer and Master Catechist for the Archdiocese of Los Angeles, is a member of Our Lady of Perpetual Help parish in Santa Clarita. He responds to comments sent to Locksley69@aol.com.)