Matthew 24:36-44But of that day and hour knoweth no man, no, not the angels of heaven, but my Father only. 37But as the days of Noe were, so shall also the coming of the Son of man be. 38For as in the days that were before the flood they were eating and drinking, marrying and giving in marriage, until the day that Noe entered into the ark, 39And knew not until the flood came, and took them all away; so shall also the coming of the Son of man be. 40Then shall two be in the field; the one shall be taken, and the other left. 41Two women shall be grinding at the mill; the one shall be taken, and the other left.

42Watch therefore: for ye know not what hour your Lord doth come. 43But know this, that if the goodman of the house had known in what watch the thief would come, he would have watched, and would not have suffered his house to be broken up. 44Therefore be ye also ready: for in such an hour as ye think not the Son of man cometh.

For those whom don't know... Yes rapture isn't mentioned in any bible though here's where we get that from..
The word “rapture” in Scripture is taken from the Latin “rapio” for the two words “caught up” used in 1 Thessalonians 4:17. It has come into popular use today to refer to the Lord Jesus coming for the church, to lift her up into the heavens. One raptured is “lifted up” in love.....
Verses on rapture...
Behold, I shew you a mystery; We shall not all sleep, but we shall all be changed, In a moment, in the twinkling of an eye, at the last trump: for the trumpet shall sound, and the dead shall be raised incorruptible, and we shall be changed. For this corruptible must put on incorruption, and this mortal [must] put on immortality" (1 Cor. 15:51-53).

Here's some more facts
The word "rapture" comes from Paul's "caught up" remark in verse 17. The words "caught up" are translated from the Greek word harpazo, which means "to carry off," "****** up," or "grasp hastily." The translation from harpazo to "rapture" involved two steps: first, harpazo became the Latin word raptus; second, raptus became the English word "rapture."

"For the Lord himself shall descend from heaven with a shout, with the voice of the archangel, and with the trump of God: and the dead in Christ shall rise first: Then we which are alive and remain shall be caught up together with them in the clouds, to meet the Lord in the air: and so shall we ever be with the Lord. Wherefore comfort one another with these words." (1 Thess, 4:16-18).