It's a warning Oth = sign. Doesn't mean anything will happen tonight. It means WTFU and pay attention.

Genesis 1:14
King James Version
14 And God said, Let there be lights in the firmament of the heaven to divide the day from the night; and let them be for SIGNS, and for seasons, and for days, and years:

Joel 2:31
King James Version
31 The sun shall be turned into darkness, and the moon into blood, before the great and terrible day of the Lord come.

https://youtu.be/LpowO3-QqKA