He did not say that no one would ever know of the hour or the day of his coming.

If we conclude from these words that no man would ever know, we might as well conclude that Jesus would never know, because he said at that time that only the Father knew.

Paraphrasing his words we note he said this: 'The day of my coming no one now knows except my Father.

Neither man nor angel knows anything about it; nor do I even know,' At the same time, his words implied that conditions would change, so that others would know, because he said: "Watch therefore: for ye know not the hour your Lord doth come".

(Matthew 24:42) Why watch unless they would know when the time would arrive?
When Jesus arose from the dead he said: "All power is given unto me in heaven and in earth".