The mystery of the moving holidays
Unlike holidays such as Christmas or the Fourth of July, Easter and Passover don’t stay put on the calendar. One year they arrive in late March, and another year they don’t appear until well into April.
For many families, it can feel a little random. Why don’t these holidays just settle on a simple date like the first Sunday in April?
The answer turns out to involve the moon, ancient calendars, and a decision made nearly 1,700 years ago.
It starts with the Jewish calendar
The story begins with Passover, one of the most important holidays in the Jewish faith.
Passover follows the Hebrew calendar, which is based largely on lunar cycles. A lunar month lasts about 29½ days, which means a lunar year is about 11 days shorter than the solar calendar most of the world uses today.
To keep holidays aligned with the seasons, the Hebrew calendar occasionally adds an extra month. Even with that adjustment, the holiday still shifts each year when translated to the modern Gregorian calendar.
Passover begins on the 15th day of the Hebrew month of Nisan, which falls shortly after the first full moon of spring.
How Easter is determined
Early Christians wanted Easter to remain connected to the events surrounding Jesus’ crucifixion and resurrection, which took place during Passover.
In the year 325 AD, church leaders meeting at the First Council of Nicaea established the formula still used today:
That means three things determine the date:
Could Easter ever be fixed to one date?
Over the years, there have been occasional proposals to give Easter a permanent place on the calendar. One commonly suggested option is celebrating it on the second Sunday in April.
A fixed date could make planning easier for schools, families, and even retailers preparing for the holiday season.
However, changing Easter would require agreement among many Christian denominations worldwide, including the Catholic Church, Protestant churches, and Orthodox churches. With so many traditions involved, a change has never gained widespread approval.
Why the dates can be so far apart
Because Easter depends on both the equinox and the full moon, the holiday can shift by several weeks from year to year.
That’s why some years Easter and Passover occur close together, while other years they appear nearly a month apart.
Even in a world of digital calendars and carefully planned schedules, these holidays are still guided by traditions that began thousands of years ago. Long before smartphones sent reminders about egg hunts or family dinners, people looked to the sky to mark the seasons.
So the next time Easter or Passover seem to jump to a new date on the calendar, remember—it isn’t random at all. The timing is simply following the same rhythm of the moon and springtime that people have watched for generations.
For many families, it can feel a little random. Why don’t these holidays just settle on a simple date like the first Sunday in April?
The answer turns out to involve the moon, ancient calendars, and a decision made nearly 1,700 years ago.
It starts with the Jewish calendar
The story begins with Passover, one of the most important holidays in the Jewish faith.
Passover follows the Hebrew calendar, which is based largely on lunar cycles. A lunar month lasts about 29½ days, which means a lunar year is about 11 days shorter than the solar calendar most of the world uses today.
To keep holidays aligned with the seasons, the Hebrew calendar occasionally adds an extra month. Even with that adjustment, the holiday still shifts each year when translated to the modern Gregorian calendar.
Passover begins on the 15th day of the Hebrew month of Nisan, which falls shortly after the first full moon of spring.
How Easter is determined
Early Christians wanted Easter to remain connected to the events surrounding Jesus’ crucifixion and resurrection, which took place during Passover.
In the year 325 AD, church leaders meeting at the First Council of Nicaea established the formula still used today:
Easter is celebrated on the first Sunday after the first full moon following the spring equinox.
That means three things determine the date:
- The spring equinox (around March 20 or 21)
- The first full moon after the equinox
- The first Sunday after that full moon
Could Easter ever be fixed to one date?
Over the years, there have been occasional proposals to give Easter a permanent place on the calendar. One commonly suggested option is celebrating it on the second Sunday in April.
A fixed date could make planning easier for schools, families, and even retailers preparing for the holiday season.
However, changing Easter would require agreement among many Christian denominations worldwide, including the Catholic Church, Protestant churches, and Orthodox churches. With so many traditions involved, a change has never gained widespread approval.
Why the dates can be so far apart
Because Easter depends on both the equinox and the full moon, the holiday can shift by several weeks from year to year.
That’s why some years Easter and Passover occur close together, while other years they appear nearly a month apart.
Even in a world of digital calendars and carefully planned schedules, these holidays are still guided by traditions that began thousands of years ago. Long before smartphones sent reminders about egg hunts or family dinners, people looked to the sky to mark the seasons.
So the next time Easter or Passover seem to jump to a new date on the calendar, remember—it isn’t random at all. The timing is simply following the same rhythm of the moon and springtime that people have watched for generations.