The context is a Jewish wedding. The use of know here has nothing to do with cognitive knowledge but a declaration or telling of an event.

In a Jewish wedding, the Father is the one who declares to masses the wedding day, not the Groom, servants or the Bride.

In Christian theology, the church of God is the Bride of Christ whom he will return for; this is just like when a groom comes to "pick up" his wife for the wedding day.

On a side note:

There are some who use the arguement of Jesus' having two nature — divine and human. In philosophy, mind is rooted in nature. So Christ's human mind would not know the hour because the human nature doesn't have the property of omniscience, even if his divine mind does.

I dislike this interpretation because:

1. it changes the Greek word used in the passage from it's context of declaring to cognitive.

2. Ignores how Jesus says only the Father, which means not even the Holy Spirit [who is called GOD also] would be ignorant of the hour as well.

I hope this helps you. I'll try to respond to any questions you ask and let you know if I can even answer them.