Note 17 at 1 Th. 5:1: It is interesting that Paul said it was not necessary for him to write about the times and seasons concerning the "day of the Lord" (v. 2). Yet there is great debate about these very issues today. Why didn't he need to inform them? The next verse goes on to mention the surprise that the event would be to everyone.

What he's saying is that no one can know the exact time or season of the Lord's return. The day of the Lord would come as a thief in the night. It would be unexpected and sudden (v. 2). Therefore, there's no point in trying to pinpoint that time. Jesus said, "But of that day and hour knoweth no man, no, not the angels of heaven, but my Father only" (Mt. 24:36). Jesus' disciples asked Him again about the time of His return just before His ascension, "And He said to them, It is not for you to know the times or the seasons, which the Father hath put in his own power" (Acts 1:7).

So, twice the Lord stated that there was no way for us to know the time of His return, and Paul is following that same reasoning with his statements here. Anyone who tries to get around this by saying they may not be able to predict the exact time but they can come within a day or week of the actual time is missing the point (see note 28 at Mk. 13:32, p. 460).