We all would love to know when, even the disciples did, before Jesus ascended:

Acts 1:6 When they therefore were come together, they asked of him, saying, Lord, wilt thou at this time restore again the kingdom to Israel?

 7 And he said unto them, It is not for you to know the times or the seasons, which the Father hath put in his own power.

But he said that it is not for them to know the times or the seasons.

He had also, previously said something similar:

Matthew 24:36 But of that day and hour knoweth no man, no, not the angels of heaven, but my Father only.

There he said that no man knows the day and hour.

So by looking at both passages, it would mean that we do not know the times, the seasons, the day, nor the hour.

All of them are not known.

So when Paul wrote to the Thessalonians:

I Thessalonians 5:1 But of the times and the seasons, brethren, ye have no need that I write unto you.

 2 For yourselves know perfectly that the day of the Lord so cometh as a thief in the night.

He wasn't implying that they did know, but rather in agreement with Jesus, that they did not know.