Understanding the timing of Easter and Passover requires looking at two distinct calendars and traditions. While these springtime celebrations often occur near one another, their origins and methods for date calculation are fundamentally different. Easter is a moveable feast central to Christian liturgy, determined by a complex formula involving the vernal equinox and the lunar cycle. Passover, or Pesach, is a fixed holiday on the Hebrew calendar, commemorating the Exodus from Egypt and beginning on the 15th day of the month of Nisan. The relationship between these dates is a frequent source of curiosity for scholars, travelers, and anyone planning seasonal events.
How Easter Dates Are Determined
The date of Easter Sunday is based on the first Sunday following the first full moon occurring on or after the March equinox. This rule, established at the Council of Nicaea in 325 AD, was designed to standardize the celebration across the Christian world and align it with the Jewish Passover of that time. The equinox is set as March 21st, even though astronomical events can vary slightly. Consequently, Easter can fall anywhere between March 22nd and April 25th, creating a wide annual window for the holiday.
The Computus and Calendar Reform
Calculating the exact date involves a mathematical process known as the computus, which historically required intricate charts and formulas. The adoption of the Gregorian calendar in 1582 adjusted the leap year system to better align the calendar with the solar year, shifting the equinox slightly. This reform created a divergence between the dates observed in Western Christianity (Catholic and Protestant) and Eastern Orthodoxy. The Eastern churches often use the Julian calendar for their calculations, resulting in a later observance that can sometimes differ by several weeks.
The Fixed Nature of Passover
In contrast to the floating date of Easter, Passover is a fixed holiday on the Hebrew calendar, which is lunisolar. It begins on the 15th day of Nisan, a month that aligns with the spring season in the Northern Hemisphere. Because the Hebrew calendar year is approximately 11 days shorter than the solar year, a leap month is added seven times every nineteen years to keep the holidays in their correct seasonal position. This ensures that Passover always occurs during the spring, fulfilling the biblical mandate to observe it "in the month of spring."
Comparing the Timelines
Due to the different methodologies, the public celebration of Easter and Passover does not always coincide on the same day. In some years, the Easter vigil falls within the Jewish holiday of Passover, creating a significant overlap in the spring season. In other years, the dates are separated by weeks. Below is a summary of recent and upcoming alignments to illustrate the variance between the two observances.
Year | Passover (Starts at Sunset) | Easter Sunday
2023 | April 5 | April 9
2024 | April 22 | March 31
2025 | April 12 | April 20
2026 | April 2 | April 5
