Seriously? https://answersingenesis.org/astronomy/stars/what-will-happen-september-23-2017/
http://www.watchfortheday.org/1260tetrad.html
On September 23, 2017 there are four planets in the vicinity that complete the sign and its ultimate uniqueness. Mercury, Venus, Mars, and Jupiter play their parts. Above the head of Virgo is the constellation Leo. In Leo at this time there will be Mars, Venus, and Mercury. With Leo being a constellation of nine principle stars, the three wandering stars make it twelve at this time. Thus the garland of twelve stars is upon the woman. For three planets to be in Leo at this time with all of the other preconditions makes this rare. Combined with the final piece of the picture below is what makes this sign difficult of not nearly impossible to replicate anywhere close to the time in which we live. How rare? A search 150 years before and 150 years after September 23, 2017 produced no results.
How rare? Try once in 7000 years according to what I have picked up. Myself, I give a very high probability that September 23 matches Rev. 12:1. Just another significant marker for this time in history. The salvation of souls is what is important now. God bless.