'Day of the Lord' in the Bible

Alas for the day! for the day of the LORD is at hand, and as a destruction from the Almighty shall it come.

Blow ye the trumpet in Zion, and sound an alarm in my holy mountain: let all the inhabitants of the land tremble: for the day of the LORD cometh, for it is nigh at hand;

And the LORD shall utter his voice before his army: for his camp is very great: for he is strong that executeth his word: for the day of the LORD is great and very terrible; and who can abide it?

The sun shall be turned into darkness, and the moon into blood, before the great and the terrible day of the LORD come.

Multitudes, multitudes in the valley of decision: for the day of the LORD is near in the valley of decision.