"But of that day and hour no one knows, not even the angels of heaven, but my Father only." Matthew 24:36
From this scripture we clearly see that no one knows the exact hour when this will happen. I believe that the rapture event is a mystery for a reason and no wonder why, knowing that we as human kind want always to know exactly when something is going to take a place and in which way is going to happen. It is hard for us to believe, to take something by faith. Meaning that when someone believes, he trusts completely that God is going to do something in His way, in His will and time. That person is confident in God. He knows that whatever it is, it will happen in the best way and that is the way of God, he knows that He is in control.
But instead of this the man in general doesn't want to lose control of his life, he wants to be the one controlling each event and that's why he doesn't like to believe, to trust with his life in God.
Taking the rapture event as an example, most of the people want to know exactly when is that going to take a place, just to be in control, just to be ready then. Why not maybe, they can live in the way they want to and when the rapture is about to come, then they will repent. This is the thought in the man's heart in general. While God made it in a way for this and many other things to be taken by faith, so that we can trust completely with all our heart to be ready and to wait on God. To believe doesn't mean that we know everything or that we control something, but it means that we trust in God and He is in control. It means that we trust in His way. We don't even know when our own end will come. God set it in this way, because probably He knows that if we knew everything and maybe we lived in our own way knowing that the rapture or our own end was going to be still far, then to repent for us was also going to be harder.
But He knows what is the best for us and we need to trust Him. Somethings like the rapture aregoing to remain a secret for us, for a reason, so that we can be always watchful and we can have the right attitude in our heart.
There can be signs trough which we can see if the time is approaching, but yet we don't know when exactly. "Now learn this parable from the fig tree: When its branch has already become tender and puts forth leaves, you know that summer is near. So you also, when you see all these things, know that it is near - at the doors!" Matthew 24:32,33
So it means that looking at the signs and what is happening aruond us, we will be able to see in part that the time is approaching, but we still won't be able to know the exact hour and moment.
That's why we will only find out when it happens. Until then we will need to do what Matthew 24:42 says and live by faith.
"Watch therefore, for you do not know what hour your Lord is coming."