Matthew 24:29
"But immediately after the terrible trouble of those days, [i.e., the next major event on God's calendar], the sun will become dark, and [therefore] the moon will not [be able to] shed its [reflected] light. The stars will fall from the sky and the forces of the heavens will be shaken [Note: From the description of these same events in Luke 21:25-26, it is possible that this is figurative language for great calamities happening on the earth].
Luke 21:25
"Then [Note: This event answers to the "immediately" of Matt. 24:29, and suggests the next major event on God's calendar] there will be [supernatural] signs [evident] in the sun and moon and stars. And on earth [there will be] distress among nations; they will be perplexed by the roaring of the ocean's churning waves. [Note: Probably this is figurative language for highly agitated conditions on earth].
Revelation 6:12-13
Then I looked as the Lamb broke open the sixth seal, and there [I saw] a great earthquake; the sun turned as black as sackcloth made out of [goat] hair, and the entire moon turned [as red] as blood.
Matthew 27:45
Now from noon until three o'clock in the afternoon there was darkness over all the land.
Mark 13:24-25
"But after those days of terrible trouble [i.e., the next major event on God's calendar will be], the sun will become dark, and [therefore] the moon will not [be able to] shed its [reflected] light,