If there was a sign for the parousia Jesus would have told his disciples.
Hi Van,
He did. “What will be the sign of your Parousia.” answer: preaching, etc.
But since there wasn't a sign he said, "at a time you think not the Son of Man cometh.
He was referring to “ that day and hour”( no one knows ) during the days of his Parousia and he explains by liking it to the the days of Noah to the days of the Son of Man—DAYS not day. Vis-à-vis on the DAY the son of man is REVEALED.