The sun will become a void of darkness, and the moon will become blood just before the great and dreadful day of the Eternal One arrives.

The sun will become a void of darkness, and the moon will become blood. Then the great and dreadful day of the Lord will arrive,

When the Lamb broke the sixth seal, a great earthquake shook the earth and the sun grew dark and became black (like mourning sackcloth) and the full moon became red like blood.