'Day' in the Bible

Yahweh is good, a stronghold in the day of trouble; and he knows those who take refuge in him.

The shield of his mighty men is made red. The valiant men are in scarlet. The chariots flash with steel in the day of his preparation, and the pine spears are brandished.

Your guards are like the locusts, and your officials like the swarms of locusts, which settle on the walls on a cold day, but when the sun appears, they flee away, and their place is not known where they are.