From our June 2016 Newsletter

Did you notice that we celebrated Easter a month before our Jewish friends and neighbors celebrated passover? Several people asked me why that is since so much of the story around Easter (The Lord's Supper, Good Friday, Easter Sunday) take place during the passover celebration. After doing some research, here's what I found:

In 325 AD (or CE), Emperor Constantine of the Roman Empire brought together bishops and church leaders to meet and talk about their differences. One of the issues this First Council of Nicaea debated was the date of Easter. Prior to this council, different churches in different places celebrated Easter on different dates. Many celebrated Easter after Passover and relied on the local Jewish communities to calculate when Passover would take place. But some felt that this calculation wasn't correct. Since the Jewish calendar is a lunar calendar (a little more than 354 days long), some calculation and adjustments were needed to help it fit a solar year (1 trip around the sun). This means that calculating Passover was tricky and that the date moves around. Sometimes this caused Passover to take place before the spring equinox (around March 21) and Easter would not fall on a Sunday. This didn't work for other Christians. After debate, the council resolved to calculate Easter on their own and not rely on the Jewish calendar. Not everyone agreed to this (we have sermons from the late 300s attacking the practice) and the actual calculation for Easter wasn't agreed on. It would take several more centuries for this to be sorted out. The church decided that March 21 will be its starting point. The formula is that Easter will be the first Sunday after the Full Moon following March 21 unless that Full Moon falls on a Sunday (in which case Easter would be the following Sunday). 

So why do churches in the West (Roman Catholic, Lutheran, Episcopalian, Baptist) usually celebrate Easter on different dates than Eastern churches (Greek Orthodox, Russian Orthodox)? It's because of the calendar we use. In 46 BC (or BCE), Julius Caesar implemented a new calendar system called the Julian calendar. Each year has 365 days with an extra day added to the calendar every 4 years (leap years). In a Julian calendar, the average year is 365.25 days long. However, scientists know that it takes less than 365.25 days for the earth to travel around the sun (365.24 days). This isn't much but, after centuries, the calendar starts to move away from where the Earth is in its rotation around the Sun. Eventually, the Spring Equinox wasn't in March anymore! So, in 1582, a new calendar was introduced (Gregorian). That's the calendar we're used to and matches how most governments keep dates. But the Eastern churches still use a Julian calendar to calculate their religious festivals. Currently, there's about a 13 day difference between the Gregorian calendar and the Julian. Eastern and Western churches do, sometimes, celebrate Easter on the same day but due to different calendars, Easter is celebrated at different times.