Why Easter and Passover are observed on different dates each year

Today is the day members of the Jewish faith begin observing Passover, which spans April 5-13, 2023. Christians will celebrate Easter on Sunday, April 9, 2023. The observances make for one of the holiest times of the year for both faiths.

While they commemorate unrelated events, Passover and Easter fall very close to one another on the calendar.

Except for when they don’t. Here's why Easter and Passover are observed on different dates each year and how the date of each holiday is determined.

Miracle Mile: Passover is time to help the community 'hit pause' at one of Phoenix's oldest Jewish delis

How are the dates of Easter and Passover determined?

Unlike most holidays, Passover and Easter aren’t anchored to specific dates. The reason for that lies with the moon.

Easter and Passover dates are pegged to the lunar calendar, where months are measured by how long it takes the moon to go from new to full and back to new. That cycle takes about 29½ days, making a lunar year about 12 days shorter than a solar year (tracked by the calendar on your wall).

That means Easter and Passover fall on different dates each year.

Holy Week and Easter 2023: How Christians observe the religious holiday

How is the date of Easter determined?

Let’s start with Easter, as its timing is not quite as complex as that of Passover.

Christians celebrate Easter Sunday as the day when Mary discovered the empty tomb of Jesus following his resurrection. Many churches hold sunrise services because Mary made her discovery at daybreak.

Easter is observed on the first Sunday after the first full moon of spring, meaning it can fall anywhere from March 22 (the day after the vernal equinox) to April 25.

Easter’s date is anything but arbitrary. Knowing the resurrection occurred on a Sunday during Passover, officials during the first centuries of the church debated Easter’s timing since Passover’s dates change each year. Was a fixed date more important, or the fact it should be celebrated on a Sunday?

By the fourth century, leaders agreed on the first Sunday after the full moon on or after the spring equinox.

How is the date of Passover determined?

Passover's dates also are tied to the lunar cycle.

The seven-day observance commemorates the liberation of Jews from slavery in Egypt, as told in the Book of Exodus in the Hebrew Bible. When God unleashed the 10th plague, slaying the first-born of each Egyptian family, he “passed over” homes of the Jews.

Passover’s dates are pegged to the Hebrew calendar, based on the lunar cycle. It starts in the middle of the month of Nisan, when the moon is full, typically falling in March or April of the Gregorian (modern) calendar. As a result, Passover typically begins very close to Easter.

However, that timing is thrown off by the shorter Hebrew calendar. Every few years, a leap month is added — an extra 29 days — to keep pace with the seasons. When this happens, it can push mid-Nisan past the second full moon of spring, thus distancing Passover from Easter.

More: What is Passover? Why is it celebrated? What you need to know about the Jewish holiday

Easter and Passover dates for the next 5 years

It may sound confusing, but dates are easily calculated for decades in advance. Here are upcoming dates per https://www.census.gov and https://www.hebcal.com.

  • In 2024, which is a leap year, Easter is March 31 and Passover starts April 22.

  • In 2025, Easter is April 20 and Passover starts April 12.

  • In 2026, Easter is April 5 and Passover starts April 1.

  • In 2027, Easter is March 28 and Passover starts April 21.

  • In 2028, Easter is April 16 and Passover starts April 10.

This article originally appeared on Arizona Republic: Why Easter and Passover are observed on different dates each year