'Day' in the Bible

But by whom may the day of his coming be faced? and who may keep his place when he is seen? for he is like the metal-tester's fire and the cleaner's soap.

And they will be mine, says the Lord, in the day when I make them my special property; and I will have mercy on them as a man has mercy on his son who is his servant.

For see, the day is coming, it is burning like an oven; all the men of pride and all who do evil will be dry stems of grass: and in the day which is coming they will be burned up, says the Lord of armies, till they have not a root or a branch.

And the evil-doers will be crushed under you, they will be dust under your feet, in the day when I do my work, says the Lord of armies.

See, I am sending you Elijah the prophet before the day of the Lord comes, that great day, greatly to be feared.