'Darkness' in the Bible

For, lo, he that formeth the mountains, and createth the wind, and declareth unto man what is his thought, that maketh the morning darkness, and treadeth upon the high places of the earth, The LORD, The God of hosts, is his name.

Woe unto you that desire the day of the LORD! to what end is it for you? the day of the LORD is darkness, and not light.

Shall not the day of the LORD be darkness, and not light? even very dark, and no brightness in it?