The Easter Bunny is grumpily collecting eggs a lot sooner than usual, hopping about from chicken coop to chicken coop on big hind feet that tingle with the ground's cold. "March 23," he pouts. "Why can't Easter be on a nice, sunny, bright April 10? Hummp. March 23.

"Last time it was this early in the ear — I mean year — was about 1913, seems to me," Bunny muses. "Yes, that was a frosty Easter, all right. Street cars frozen to the tracks. ... At least it won't pop up this soon again for a while."

The rabbit's right.

Sunday will mark the earliest Easter the world has experienced in 95 years, and unless human life expectancy improves immensely, nobody alive today will see another Easter this early in the year.

March 22 is the first date on which Easter can be celebrated, and March 23 is the second-earliest. The last time March 22 hosted the holiday was in 1818, according to an online calculator posted by the U.S. Naval Observatory at A chart for recent years is also at the observatory's site:

A laborious check by the Deseret Morning News of all dates for Easter from 1800 through 2160 confirms that the next time Easter will be this early in the year is 2160.

The check also turned up these Easter tidbits: The earliest it has been observed in the past 70 years was March 24, 1940, and March 26, 1989; Easter fell on Mach 23 in the years 1845, 1856 and 1913.

Why is the holiday celebrated on so many different dates? The story goes back to the days of the Roman Empire.

According to the Naval Observatory, based in Washington, D.C., the emperor who converted to Christianity, Constantine I, convened the Council of Nicaea in the year 325. The Roman world was using the Julian calendar at the time, an innovation of Julius Caesar, who had died more than 280 years before.

Setting aside controversy about that council's work to enforce its version of Christian orthodoxy, one ruling it made affects Easter. A Naval Observatory publication explains, "The council decided to keep Easter on a Sunday, the same Sunday throughout the world.

"To fix incontrovertibly the date for Easter, and to make it determinable indefinitely in advance, the council constructed special tables to compute the date."

In 1582 Pope Gregory XII reformed the calendar. With the new Gregorian calendar, leap years were included in the calculations for Easter.

The usual way of describing Easter is that it is on the first Sunday after the first full moon that occurs after the vernal equinox, the observatory notes.

But that's not the whole story, it adds. The full description is:

— Easter falls on the first Sunday following the first ecclesiastical full moon that occurs on or after the day of the vernal equinox.

— The date of that full moon isn't determined by watching the heavens and noting when the moon is largest. Instead, by these rules, it is calculated as the 14th day of the lunar month, with the first being the new moon.

— Even though the date of the vernal equinox, the spring day in which the sun is directly over the equator, varies from year to year, for the purpose of the calculation the vernal equinox is arbitrarily fixed as March 21.

The result is that Easter can never be before March 22 nor after April 25.

To make the situation even more complex, Western churches use the Gregorian calculations but some, notably the Eastern Orthodox and related churches, use tables based on the Julian calendar.

"Can't wait 'till next year," mutters Bunny. "Then Easter will be on April 12."