One does not need to know even an approximtate date of Jesus’ return in order to NOT be surprised when it happens. In fact, that is the nature of the Christian life - living in constant readiness for His return. Believe me, there is nothing “lazy, lackadaisical or lukewarm” about that.
It seems to me that the people who may be the most surprised are those who are obsessed with date-watching and guessing, quite simply becasue they have taken their eyes off the prize.
“Therefore you [Jesus’ disciples] also be ready, for the Son of Man is coming at an hour you [Jesus’ disciples] do not expect.” (Matt. 24:44)
Anyone who tells you differently is scamming you, including the author of this bit of whimsy.