The Bible does not give us the exact date of Christ's crucifixion, or even enough indirect information to pin it down with certainty. However, the crucifixion coincided with a partial eclipse of the Moon, and this helps us decide on the most likely date.

The only certainty about the date of the crucifixion in the Bible is that took place during the ten years that Pontius Pilate was in charge of Judea. This was from A.D. 26 to 36.

There is a complication in trying to date biblical events. Our months and days do not coincide with those of the Jewish calendar, which is implicit in the information given in the Gospels. Jewish days start and end at 6pm in the evening, and Jewish months straddle our months.

All the Gospels agree that Jesus died a few hours before start of the Jewish Sabbath. This commences at 6pm on a Friday evening. The Gospels agree to within a day that it was the time of the Passover - the annual Jewish feast held at the time of a full Moon. Newton's Laws of Motion allow us to calculate when the Moon is full - not forgetting of course that it is a full Moon as viewed from Jerusalem that is needed.

Passover time was precisely specified in the official Judean calendar. It took place on the 14th day of the Jewish month that straddles our March and April. The Passover meal had to begin at moonrise that evening. Again Newton's Laws allow calculation of the time of moonrise (as viewed from Jerusalem).

It is recorded in the so-called "Report to Pilate" (a documentary fragment from the New Testament Apocrypha) that at Christ's crucifixion " ... The moon appeared like blood." The phrase "the moon appeared like blood" almost certainly refers to an eclipse of the moon.

For an eclipse of the moon, the Earth comes in between the moon and the sun, and so casts a shadow on the full moon. The reason the moon is red is easy to explain. Although in the Earth's shadow, some sunlight still reaches the moon by being refracted (or bent) by the Earth's atmosphere (just like light in a prism). While travelling through the Earth's atmosphere all the colours that make up white light (the rainbow) except red are easily scattered by
the gasses and dust in the air. So it is mostly red light that travels on to illuminate the Moon.

Newton's Laws can be used to calculate to a few seconds the times of all past lunar eclipses. In the period AD26 to 36 there was only one lunar eclipse at Passover time visible from Jerusalem. The date referred to out calendar is Friday 3 April AD33.

On that day moonrise did not occur until 6.20pm, just after the start of the Sabbath when the Passover feast was to start. The moon would have appeared with about 20% of its disc eclipsed. It would have been observed my most of the population of Israel, since the Jews on Passover day would have been looking for sunset to signal the start of the Sabbath, and Moonrise to signal the start of the Passover meal. Instead of seeing the expected full "paschal moon" they would have seen a full Moon with a large red crescent superimposed upon it. The effect would have been very dramatic.

Finally, it is interesting to note that the Last Supper could not have been
a Passover meal, and this may lie at the heart of the confusion in the
Gospels as to the actual day of the crucifixion.

[This article is based on the scientific paper published in Nature by C J
Humphreys and W G Waddington, 22/29th December 1983, pages 743 to 746]

Rick Marshall


Using Astronomy to date the Crucifixion

By Rick Marshall