article_snippet.sent: (CNN)Easter is a cornerstone event in the Christian faith, but CNN)Easter's surrounded by interesting quirks.
article_snippet.sent: CNN)Easter celebrates the completion of Christ's mission of salvation in the Crucifixion and Resurrection.
article_snippet.sent: Here's a journey from the Vatican to the Holy Land, around the moon and the Earth's tilting axis, to Germany and the United States to try to explain the complex holiday called Easter.
article_snippet.sent: Let's move on to old Jerusalem, the birthplace of Easter.
article_snippet.sent: It's not quite Easter yet in the Holy Land for Eastern Orthodox Christians.
article_snippet.sent: a large group of indigenous Christians'll be celebrating a week from now, because a large group of indigenous Christians determine Easter's date by a different calendar than Western Christians -- the Julian calendar.
article_snippet.sent: Not completely, because the dates for both Passover -- the Jewish holiday celebrating the deliverance from slavery in Egypt -- and Easter are determined by moon phases, according to timeanddate.com.
article_snippet.sent: Easter's timing is related to Passover, because Jesus was crucified around then, according to the Bible.
article_snippet.sent: Since the timing of moon phases doesn't jibe with Earth's orbit -- which is how we determine the length of a year now -- Passover's exact date moves around -- and so does Easter's.
article_snippet.sent: When Christian bishops first convened at the Council of Nicaea in the year 325, Christian bishops made a rule to determine the date of Easter, so as to fairly reliably pin a rule to Passover: .
article_snippet.sent: When the West moved from the Julian calendar to the Gregorian calendar, Orthodox Christians stayed put, resulting in -- usually -- two separate dates for Easter.