You do not know: Jesus had said this before and now stresses it again. See notes on Matthew 24:42, 50; Mark 13:33. Just before the moment of his ascension Jesus told his disciples, “It does not belong to you (apostles) to know times of appointed times which the Father has placed within His own authority.” Despite these clear instructions pseudo prophets have predicted a variety of dates based on their own interpretations of the Bible.
“So, then, let us not continue to sleep. But rather, let us stay awake and remain sober.” (1Th 5:6 mhm)
“Remain sober. Remain awake. Accusing you at court, your Adversary the Slanderer is walking about like a roaring lion seeking to swallow you down.” (1Pe 5:8 mhm)