Revelation 6:11-13 New King James Version (NKJV)
11 Then a white robe was given to each of them; and it was said to them that they should rest a little while longer, until both the number of their fellow servants and their brethren, who would be killed as they were, was completed.
Sixth Seal: Cosmic Disturbances
12 I looked when He opened the sixth seal, and [a]behold, there was a great earthquake; and the sun became black as sackcloth of hair, and the [b]moon became like blood. 13 And the stars of heaven fell to the earth, as a fig tree drops its late figs when it is shaken by a mighty wind.