FOR IMMEDIATE RELEASE: February 28, 2000

FOR MORE INFORMATION: Glenn A. Walsh, Life Trustee, Andrew Carnegie Free Library

(412) 276-3456, (412) 561-7876, <>



Carnegie, Pa., Feb. 28 - February 29, 2000 marks a very special leap year-day; one that is observed only once every 400 years! This is the first time this day has been observed in the United States. This is the second time this special leap year-day has been observed, since its establishment in 1582.

Leap years began when Julius Caesar started the Julian Calendar in 45 B.C. At that time, the year was believed to be exactly 365.25 days in length. Hence, the Julian Calendar added one day every four years, commonly referred to as "Leap Year," to ensure that, over time, the seasons would not move from their normal time of year. The extra day was added to February, which was then the last month of the calendar year; the New Year began near the Spring Equinox in March.

The year is actually 365.2422 days in length. Having a leap year every four years meant that an additional eleven minutes were added to the calendar every four years. As time passed, this error added up and the calendar slowly fell out of step with the seasons.

By the late sixteenth century, the error had accumulated to ten days. The Spring Equinox, which was supposed to fall on March 21, now fell on March 11. Easter was now being celebrated on the wrong day, which brought the matter to the attention of Pope Gregory XIII.

On October 4, 1582, Pope Gregory decreed that the following day would be October 15, 1582, hence bringing the calendar back in step with the seasons.

His second decree changed the leap year rule. No longer would there be a leap year every four years. Now, a leap year would not occur on a year ending in two zeros, unless that year was divisible by 400; in all other cases, leap years would occur in years divisible by four.

The Pope's calendar reform was adopted immediately in predominantly Catholic countries. The "Gregorian Calendar" was not adopted in Great Britain and her American colonies until 1752, in Japan in 1873, and was imposed in Russia immediately following the Communist Revolution in 1918.

Hence, 1900 was not a leap year but 2000 is a leap year. After this year, leap years will continue to be observed every four years until 2100, which is not a leap year. The years 2200 and 2300 will also not be leap years, but 2400 will be a leap year.

In most years, a particular day, say March 1, moves to the next day of the week each year(from Sunday in 1998 to Monday in 1999). However, in a leap year, March 1 "leaps" from Monday in 1999 to Wednesday in 2000. Hence, the term "leap year" was coined.

Although Pope Gregory's calendar reform was a great improvement, even it was not perfect. It is predicted that another adjustment to the calendar will need to be made in approximately 3,000 years !