The total lunar eclipse near the end of the month, a blood moon, gives prophets of doom a second chance to be right.
If the partial solar eclipse of 13 Sep doesn't deliver the End of Days and Second Coming, then the September blood moon, a total lunar eclipse tinged red, must surely deliver the coup de grace for Mankind. It is seen as a portent because it is the last in a rare tetrad of blood moons.
The first date in September, on the 13th, a partial solar eclipse, cues apocalyptic prophecies because it coincides with the Jewish holy day of Rosh Hashanah.
The September blood moon promises to be a stronger portent for the Apocalypse because the Bible foretells it: "The sun shall be turned into darkness, and the moon into blood, before the great and the terrible day of the Lord comes," [Joel 2:31]. It is given more significance because it is the last of a highly unusual tetrad. NASA describes a tetrad as four successive total blood-red lunar eclipses each followed by six full moons. These started on Apr 15, 2014, then followed on Oct 8, 2014 and Apr 4, 2015. The fourth falls on the September date.
Some people believe that the tetrad has special significance because the eclipses coincide with important Jewish festivals. The two April lunar eclipses in 2014 and 2015 occurred at the same time as Passover, while the October and September eclipses occur during the Feast of Tabernacles.
The tetrads are rare - the last occurred in 2003, and there were none between 1600 and 1900, but they have happened often enough that the prophets of doom might be growing discouraged that Mankind hasn't yet succumbed. Some of the prophets avoid the embarrassment of being wrong by linking astronomical anomalies to war, and not to the Apocalypse. They are always wars enough for them to be right.
Date written/update: 2015-07-01