The Easter date depends on the ecclesiastical approximation of the March equinox. In 325CE the Council of Nicaea decided that the Easter date would be the first Sunday after the first full moon occurring on or after the March equinox. Easter is therefore delayed one week if the full moon is on Sunday, which lessens the likelihood of it falling on the same day as the Jewish Passover. Eastern Orthodox churches in many countries such as Greece still figure their Easter date based on the Julian calendar