The evidence is for a Friday crucifixion is plentiful, once we're ready to start looking into what non-Biblical sources say about the astronomical events surrounding the crucifixion of Jesus Christ.
Phlegon was a Greek historian who wrote an extensive chronology around AD 137:
In the fourth year of the 202nd Olympiad (i.e., AD 33) there was ‘the greatest eclipse of the sun’ and that ‘it became night in the sixth hour of the day [i.e., noon] so that stars even appeared in the heavens. There was a great earthquake in Bithynia, and many things were overturned in Nicaea.’Phlegon identifies the year and the exact time of day. In addition, he writes of an earthquake accompanying the darkness, which is specifically recorded in Matthew’s Gospel.- Phlegon, 137 AD
This event could not have been a solar eclipse in the classic sense. In other words, whatever caused a shadow to fall over the earth, and the sun's light to be blotted out, could not have been the moon. As the moon is always in the completely opposite position in the sky during the full moon phase, which is what Passover always falls on. Furthermore, solar eclipses just last a few minutes, never three hours. The three-hour "eclipse-like" event is a historical fact, and accounted for by non-biblical (even non-Christian) authors, including Pontius Pilate no less, who wrote in a report to Tiberius Caesar the following account...
Now when he was crucified darkness came over all the world; the sun was altogether hidden, and the sky appeared dark while it was yet day, so that the stars were seen, though still they had their luster obscured, wherefore, I suppose your excellency is not unaware that in all the world they lighted their lamps from the sixth hour until evening. And the moon, which was like blood, did not shine all night long, although it was at the full, and the stars and Orion made lamentation over the Jews because of the transgression committed by them.- Pontius Pilate, 33 AD
We may never know what caused the solar eclipse-like event that lasted three hours, but we can speculate. Assuming that God uses natural events in unexpected ways to accomplish most of his miracles, then using what we know about natural phenomena, we can make a good guess. Eclipses are caused when the shadow of something is cast on the earth. Under normal circumstances, its the shadow of the moon cast upon the earth, as the moon passes between the earth and the sun, blotting out the sun's light for a few seconds. So based on what we know causes eclipses, we can speculate that something fairly large passed between the earth and the sun on the date and time in question, and we know that it could not have been the moon. Also the duration of the event (3 hours) would seem to indicate that the trajectory of the object was such that it kept the shadow on relatively the same place (the Mediterranean world) for about three hours. One possibility would be a very large asteroid on a near collision course with the earth. If the trajectory were so that the large asteroid (several dozen miles in diameter at least) were coming directly from the angle of the sun, passing by the earth at an incredibly close range, it might create a shadow large enough to eclipse the sun wherever it was cast on the earth's surface. Furthermore, such a near miss with such a large object would certainly capture the object in the earth's gravitational well, causing the asteroid to be flung around the earth at a totally different trajectory than when it came in. If the asteroid were to have it's own gravitational pull, and something that size probably would, then it might have caused disturbances on the earth as it passed by in the form of natural disasters, such as earthquakes. Granted this is all just speculation, but I am unaware of any other natural occurrence that could cause an eclipse-like event lasting three hours, coupled with earthquakes, like the one described by so many sources from antiquity. I should like to see more study into this possibility done by people more well versed in astronomy and astrophysics than myself.
The occurrence of a blood red moon is actually much more easy to explain. Pilate's account to the red moon also helps us confirm not only the year, but the actual day. NASA has already accounted for the only kind of eclipse that can happen in a full moon phase, which is a lunar eclipse, frequently known to give the moon a "blood red" appearance, particularly when they are seen only partially. NASA pinpoints this event to April 3rd, 33 AD. The following chart is their report, which can be viewed on NASA's actual website here...
Finally, we must look to the Jewish calender to verify that a Passover did occur on this date. Indeed it did. Nissan 15, the customary day for Passover, would have fallen on Saturday the 4th of April in 33 AD. That would have made this particular Saturday a "high sabbath" which is mentioned in the gospel accounts, and it would have made Friday the 3rd of April the day of preparation, when the lamb sacrifice was slaughtered in the Temple. This would have put Jesus crucifixion at exactly the time when the Passover lambs were being slaughtered, just hours before sunset, when Nissan 15 began on the Jewish calendar. (Remember, the Jewish calendar begins each day at sundown not midnight.) Typically, the Passover meal would have been eaten that Friday evening in 33 AD. However, the gospels tell us that Jesus ate the Passover with his disciples the night before -- Thursday. This may be accounted for by the probability that Jesus was using the Essene calendar for the calculation of Passover.
Pope Benedict XVI, in his Holy Thursday homily for 2007 pointed out that Jesus; "celebrated Passover with his disciples probably according to the calendar of Qumran, that is to say, at least one day earlier -- he celebrated without a lamb, like the Qumran community who did not recognize the Temple of Herod and was waiting for a new temple."
So there you have it folks. The definitive date of Jesus' crucifixion is settled by two undeniable astronomical events. The first extraordinary, recorded in the gospels, and confirmed by the written testimony of non-Biblical authors. The second quite ordinary and predictable, easily calculated and illustrated by the experts at NASA. Finally, we have the confirmation of the Jewish calendar, which confirms a Passover preparation on this very day (see chart here, Passover always falls on the Jewish date of Nisan 15, with preparation and seder always on Nisan 14), just as the gospels tell us. Jesus Christ was crucified at high noon, and died at 3 pm, on Friday, April 3rd, 33 AD.