CLIFTON Bishop Kevin Sweeney served as main celebrant for the 8 a.m. and 10:30 a.m. Masses on Easter April 17 in St. Brendan/St. George Church here. Easter, the chief feast of the Church’s ecclesiastical year, commemorates the Resurrection of Jesus Christ from the dead. The date of Easter is calculated by lunar cycles — it is the first Sunday after the Paschal full moon, the first full moon occurring on or after the spring equinox — because Christ’s Death and Resurrection were linked to Passover, a feast calculated according to the Jewish lunar calendar. Easter can be as early as March 22 or as late as April 25.