Zechariah 14:7

but it shall be one day, a most singular day in every way, which shall be known to the Lord, He alone being acquainted with its true nature, not day nor night, because the lights of heaven will have lost their power to shine; but It shall come to pass that at evening time it shall be light. This picture represents the Church of the Middle Ages gradually sinking into darkness as the light of the Word of God was obscured by its leaders. Fortunately, however, the Lord, through the Reformation, caused the glorious light of His Gospel to shine forth once more.