'Day' in the Bible

when He comes on that day to be glorified in His people and to be wondered at among all who have believed, including you--because you believed the testimony which we brought for your acceptance.

not readily to become unsettled in mind or troubled--either by any pretended spiritual revelation or by any message or letter claiming to have been sent by us--through fancying that the day of the Lord is now here.

Let no one in any way deceive you, for that day cannot come without the coming of the apostasy first, and the appearing of the man of sin, the son of perdition, who sets himself against,

nor did we eat any one's bread without paying for it, but we laboured and toiled, working hard night and day in order not to be a burden to any of you.