Easter launches week of religious holidays throughout Europe

A maritime parade of decorated rowboats is part of the Marriage of the Sea ceremony, one of the celebrations of Ascension Day in Venice. (iStock) Catholic and Protestant communities throughout most of Western Europe will celebrate Easter Sunday on April 17, a date that shifts each year according to complex ecclesiastical rules put into place at the First Council of Nicaea held in 325 AD. For practical purposes, the rule of thumb that Easter Day is the first Sunday after the full moon following the spring equinox is often accurate.