A short history of time, by Leofranc Holford-Strevens, helped me with the question of knowing what day of the week Jesus died.
This one raises its head when looking at John’s gospel. One idea is that John presents Jesus’ death as at the same time lambs for Passover were being killed. (See John 19:14, and understanding ‘preparation of the Passover’ as when the Passover meal is prepared – Thursday, by modern name, for that year.)
But in the synoptics, Jesus and his disciples are clearly presented a sharing the Passover meal, on the night before the events of John 19.
What’s going on, then? Condradiction and confusion? I think not.
I think it’s most likely that ‘preparation of the Passover’ refers to the Friday. Preparation is a very common term for the pre-Sabbath day (Friday, as we name it, though the start and end would be 6pm rather than 12 midnight).
But if that were not the case, one suggestion is that the synoptics and John were referring to different calendars. Different ways of calculating Passover mean different days for killing the lamb. For an explanation of this, see Leon Morris’ The Gospel According to John. (This link is to the revised edition. In my copy of the unrevised the pages to read are 782-788.)
I now admit my prejudice. I easily dismissed the idea of different calendars. ‘How dumb is that?’, I thought, on the basis of my experience of easy access to common and worldwide dating, even given the existence of different year numbering systems (1 Jan 2011 falls in Jewish year 5771, for example).
A short history of time opened my eyes to my own failure of sympathy. My experience of calendrical stability is not universal. There certainly were differences and disputes about calendars. Holford-Strevens speaks of the readingess of some Jewish communities acting to “regulate the calendar for themselves, rather than following the Rabbis of Jerusalem” (p.82).
So it seems the ‘different calendar’ idea is not crazy like I thought it must be.