The holiday involving eggs and rabbits can tend to jump around. Source: Impact BND

The Easter holiday is here and you may have noticed that this year it has come a little bit earlier than usual. Well, it’s not a coincidence. In fact, Easter falls on a different date each year. Typically, between March 22 and April 25. Since Easter is one of the most important Christian holidays, you would expect it to have a fixed day on the calendar just like Christmas. But that’s not how it works.

This is because Easter is determined by the Jewish calendar. According to the Bible, the death, the burial, and the resurrection of Jesus Christ took place after the festival of Passover. Christians around the world have maintained the tradition of celebrating Easter the same way the Jewish do - after Passover.

There are several calendars at work here. Source: Hari Ghotra

However, it’s not as simple as it looks. Finding out which day Easter will fall involves combining both the Jewish calendar and the solar calendar used by Christians. One year in the Jewish lunar calendar has a total of 354 days while a year in the sun calendar has a total of 365 days. Combining both calendars and finding out exactly when the Easter holiday will fall can be difficult.

In addition to this, the festival of Passover is not fixed on one day. Like Easter, the date changes every year. This is because the festival is calculated by the first full moon that follows the vernal equinox. This is a phenomenon in nature where during one day in spring, the length of the day and the night is exactly the same. Before the modern calendar, it’s believed that Christians would celebrate Easter on the first Sunday following the vernal equinox.

Some lunar dates to keep in mind as well. Source: Prima

However, a new standardized calendar system was created by astronomers and it became the basis for determining when Easter should fall. A table was created by the astronomers that determined all the Ecclesiastical full moons. It was determined that all these full moons landed on the 14th day of the lunar month. Ever since the 15th century, these historical tables have been used to determine the Passover full moon or what’s also known as the Paschal full moon.

The Passover full moon is interpreted from the tables as the first full moon date after March 20. Easter is celebrated during the first Sunday following the first Passover full moon. The reason why the Easter holiday varies in terms of dates is because of the variance of the Paschal full moon. This is why Easter falls anywhere from March 22 to April 25.

Well, now you know why Easter lands on a different date each year but nonetheless, despite this curious history, Easter is indeed a very popular holiday among Christians around the world. It’s often seen as a symbol of faith in Jesus Christ and recognition of his suffering on behalf of humanity.