The answer lies in the calendars that the Jewish and Christian religions follow.
Passover falls on the same day in the Jewish calendar every year, but because that calendar is based on the lunar cycle, the celebration of Passover varies according to the Gregorian calendar, says Time.
To keep the Hebrew year aligned with the seasons of the solar calendar, the Jewish calendar includes leap years that add an extra month. Since 2016 is one of them, the extra month pushed Passover into late April.
"The ancient Israelites took their Calendar very seriously," Dorsch said. "Many significant Jewish holidays originated as agricultural holidays. Their times were fixed, in accordance with specific dates on their Lunar calendar, and their seasons."
As for Easter, the ancient Christians took their calendars seriously too, just as they took their schisms. Its date depends on which church: those that chose the western church follow the Gregorian calendar and those that chose the eastern kept the Julian calendar. And two millennia later, so do we.
Easter is a “movable” feast based on the full moon and the vernal equinox (the official start of spring).
The Old Farmers Almanac explains it: In Christian churches that follow the Gregorian calendar for determining the date of Easter, the observance can never occur before March 22 or after April 25. That was March 27 in 2016. In Christian churches that follow the Julian calendar for determining the date of Easter, the observance can occur between April 4 and May 8 (using Gregorian calendar dates).
Passover is an annual eight-day festival that includes many rituals to help celebrate the end of Jewish slavery in Egypt. The holiday lasts from Friday, April 22 to Saturday, April 30.