But of that day and that hour knoweth no man, no, not the angels which are in heaven, neither the Son, but the Father. (Mark 13:32)
Robert Haddard, an Australian Catholic apologist, addressed the question of how Jesus could not know the time of his second coming. His response (which, to be fair, he admits he himself does not find totally satisfactory) is basically, (1) as Jesus knows what would happen, this must mean he knew (intellectually) when it would happen and that (2) when Jesus stated he did not "know" the time of the second coming, this simply means that he was not allowed to reveal the timing thereof:
Why would Jesus not know the time of his second coming?
To be fair to Haddard (he seems like a smart fellow from the videos I have watched where he has defended Roman Catholic theology), "utter nonsense" is the most polite way to sum up his pathetic argument, though it is en par with the more common response of "Jesus [who is one person] did not know with respect to his human nature but did know with respect to his divine nature" (which essentially splits Jesus into two persons, a la Nestorianism, a 4th century heresy condemned at Ephesus in 431, as well as Chalcedon's affirmation that, notwithstanding having two distinct natures, Jesus is a single person in 451).
For more, see the discussion about the Hypostatic Union ("The Hypostatic Union Examined") in my article:
Latter-day Saints have Chosen the True, Biblical Jesus