Matthew 8:29

And, behold, they cried out, saying, What have we to do with thee, thou Son of God? art thou come hither to torment us before the time?

The kingdom of evil, at this point, was fully aware of WHO Christ was (and is). If Satan had any doubt prior to this, Christ's rebuke of the winds and the sea removed it. These demons freely admitted and, in a sense, confessed Jesus as the Son of God, admitting that he had the power to torment them "before the time." This shows that the time of ultimate judgment and punishment of the condemned is set for future fulfillment and that the whole demonic world is fully aware of it.