352 ÉTIENNE NODET Up to now, it has been difficult to choose between 30 and 33 on literary grounds. The references given above about John the Baptist and Jesus’ first Passover would suggest a slight preference for 33, but scholars are still divided. One could say that it is not a major problem, but Humphreys and Waddington introduce another set of astronomical considerations, the lunar eclipses visible from Jerusalem. Obviously such a phenomenon can only happen at the full moon, which implies that it can only be seen by night. A new calculation of the dates of these eclipses, which takes into account the effects of long-term changes in the earth’s rate of rotation, gives a striking result. Out of 12 such eclipses that occurred during Pilate’s tenure, only one falls on a Passover day, in 33. It occurred at moonrise, that is immediately after sunset, and had a 60% magnitude. More accurately, it started below the horizon at 3:40 p.m., reached a maximum at 5:15 p.m. and finished at 6:50 p.m.. The rising moon could be seen from Jerusalem at 6:20 p.m., with a shaded area 7. Now, in his Pentecost speech (Acts 2,20), Peter quotes the eschatological prophecy of Joel 3,1-5, which includes: “The sun shall be turned into darkness and the moon into blood, before the day of the Lord comes”. It has been shown that this refers to both eclipses, solar and lunar 8. Ancient writers used to describe the latter as “moon suffused with the color of blood”. Indeed, this is the way its shaded area appears, especially when it is low on the horizon. Of course, the prophecy is a poetic view, for both types of eclipses cannot happen on the same day 9. Moreover, the main point of the quotation is the pouring out of the Lord’s Spirit. In Rev 6,12, when the Lamb opens the sixth seal, the seer says: “There was a great earthquake, the sun became black as sackcloth, the full moon became like blood”. Here there is an allusion to Isa 13,10 (and possibly 50,3), somewhat rewritten: “The sun will be dark at This eclipse had been calculated by the astronomer J.R. HIND, “Historical 7 Eclipses ”, Nature 6 (1872) 251, but, with the data then available on the earth’s rotation, he concluded that it occurred entirely before moonrise, i.e. that it could be seen from India, but not from Jerusalem. Even in Rabbinic tradition, see Yalq. Shim’oni II :536. 8 The Sibylline Oracles § 111 solves the problem in a Messianic section: 9 “ And straight way dust is carried from heaven to earth and all the brightness of the sun fails”. This view was traditional.