This darkening of the sun it is quite plain did not happen in the regular and fixed course of the heavenly bodies, because it was then the Passover, which is always celebrated at the full moon. But a regular eclipse of the sun does not take place except at new moon.
PSEUDO-DIONYSIUS. (Dion. Areop. ad Polye.) When we were both at Heliopolis together, we both saw at the same time in a marvellous manner the moon meeting the sun, (for it was not then the time of new moon,) and then again, from the ninth hour until evening supernaturally brought back to the edge of the sun’s diameter. (ad diametrum solis.) Besides, we observed that this obscuration began from the east, and having reached as far as the sun’s western border at length returned, and that the loss and restoration of light took place not from the same side, but from opposite sides of the diameter. Such were the miraculous events of that time, and possible to Christ alone who is the cause of all things.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).
Also cites: de Civ. Dei, l. iii. c. 15.