God wants us to know that the time [of Christ's return] is definite. In his mind it's going to happen at a definite time. But you and I can never say exactly which is the date.
Christ's first coming was so obscure, that it was scarce observed and understood by the world. The second will be so conspicuous and glorious as to be seen of all. In the former, he came in the form of a servant, and the contemptible appearance of a mean man; in the second, he cometh as the Lord and heir of all things, clothed with splendour and glory as with a garment.Works, Volume 10