Easter Always Comes on a Sunday, but the Dates Are Not the Same. Here’s the Reason Why

Easter Sunday is an important yearly event for possibly every Christian. However, many have noted certain peculiarities with this holiday. It stands apart from another important holiday, Christmas, by being flexible in its date, stated IFL Science.

The Easter Sunday changes date every year, but it falls on a Sunday, no matter what. There is a very special reason behind this phenomenon. Easter Sunday is determined following the lunar calendar and not the Solar Calendar, like most holidays. The lunar calendar functions based on the moon's phases and cycles, stated AnDarach. In this calendar, each cycle happens every 29.5 days, which is different from the cycle of 28 to 31 days in Solar Calendars.
Traditionally, for Western Christians, Easter falls on the first Sunday that comes after the first full Moon following the Northern spring equinox. In 2023, Equinox occurred on March 20, stated IFL Science. Thereafter, the Pink Moon came up on April 6, 2023, hence, Easter was celebrated on April 9, the following Sunday.
The church always recognizes the date of the equinox to be March 21, stated Country Living. Depending on when the first full moon occurs after this equinox, the date of Easter is decided. Typically, it falls between March 22 and April 25. In 2025, it will be on April 20. To date, the reasons behind Easter following the Lunar Calendar have remained cloudy. Some believe it could be because of Easter's association with Passover, a holiday that celebrates Jewish people's freedom from slavery in Egypt. Since, the Hebrew Calendar follows the lunar scheme, Easter possibly also took up the same methodology. Both Passover and Easter dates fluctuate every year.

Easter is a Christian holiday that celebrates the death and later resurrection of Jesus Christ, stated IFL Science. According to mythology, the prophet was crucified on Good Friday, his body was laid to rest on a holy Saturday, and on Easter Sunday, he was resurrected. Therefore, it is essential that the holiday takes place on a Sunday. This compulsion of the holiday falling on Sunday ultimately leads to the shifting of dates.
Another event, which is Ash Wednesday, also depends on Easter, stated Country Living. This is a multiple-day festival that ends with Easter. The holiday comes from the Old Testament. The main ritual of this holiday involves a priest invoking Genesis 3:19 ("...for you are dust, and to dust you shall return.") while applying on their congregants' foreheads a mix of ash that has arrived from some practices conducted on Palm Sunday. These 40 days symbolize the period Jesus Christ spent in the wilderness. Ash Wednesday is supposed to start 46 days before Easter. The 40 days signify the journey of Christ, while the six days are acquired because the Sundays that fall in the passage of the 40 days are not considered suitable for fasting.

Though it is a task to figure out when exactly Easter will take place in a year, this shifting has now become a kind of tradition, stated IFL Science. Several attempts have been made to have Easter be celebrated on a particular day, but none of them have been considered seriously.