When does Easter really start? This simple question has a long history. Some time in the late third century, a Christian called Basilides wrote to Dionysius, the Bishop of Alexandria, to ask when the fast observed through Holy Week should give way to the celebration of Christ’s Resurrection: was it on the Saturday evening, or at cockcrow on the Sunday morning, the custom in Rome? Basilides wanted a definite answer, a precise time when the festivities should begin. The Egyptian bishop was reluctant to oblige, especially as the gospels told of visits at different times to the empty tomb. He was right to ­hesitate. Not only do the gospels fail to clock the precise moment of the Resurrection, but John’s gospel in particular explores the gradual process by which the Good News o