"Therefore be on the alert, for you do not know which day your Lord is coming. But be sure of this, that if the Head of the house had known at what time of the night the thief was coming, He would have been on the alert and would not have allowed His house to be broken into. For this reason you be ready too; for the Son of Man is coming at an hour when you do not think He will. Who then is the faithful and sensible slave whom his Master put in charge of his household to give them their food at the proper time? Blessed is that slave whom his Master finds so doing when he comes. Truly I say to you, that He will put him in charge of all his possessions."
Matthew 24:19-20
(This is bound not to clear things up for anyone, but I bet they'll think it does.)