This may already have been discussed, but as I read it today, I realized this passage should settle the question of whether or not we will know exactly when He is coming -

 

'So remember what you have received and heard; and keep it, and repent. Therefore if you do not wake up, I will come like a thief, and you will not know at what hour I will come to you.  (my bold)   Rev 3:3 (NASB)

 

So then it follows that those who are awake and watching will know the hour.