Scott Clarke has an excellent you tube channel (www.scottieclarke.com). I have recommended Scott's videos before (including yesterday) and I will recommend them again. If you don't want me to spoil his videos, go watch them before you read this. In any case, please do watch the videos because they are well worth your time.
I first became aware of Scott when Ron G linked to his video last year shortly after Rosh Hashanah. The video was called "The Most Logical RAPTURE Theory on You Tube, Period!" (http://www.youtube.com/watch?v=QW17ZP0shv0). It explains the lunar tetrads in 2014 and 2015. It also shows a sign in the heavens on September 23, 2017 that exactly matches Revelation 12:1-2. Virgo (the virgin) has the sun over her left shoulder and the moon at her feet. Jupiter (the king planet, representing Jesus) is between her legs as if she had given birth. There are twelve stars at her head. The constellation Leo with 9 stars is always at her head. But on this day, Venus, Mars, and Mercury are aligned with Regulus in Leo making 12 stars. Scott has looked for this formation in other years and cannot find it.
Scott expanded on this in a video called "The GREAT Revelation 12 SIGNS In The Heavens - Revisited & REVEALED!" (http://www.youtube.com/watch?v=JBijLdYXMFw). This video shows what happens immediately after the Revelation 12:1-2 sign. Mercury moves very close to Saturn, reverses course, and then returns for a second close encounter. Saturn then moves into Sagittarius. This may well represent the war between Michael (Mercury) and the angels versus Satan (Saturn) after which Satan is cast down to the earth and indwells the Antichrist (Sagittarius).
As if this weren't compelling enough, Scott released a new video today called "PROPHECY in Your FACE with a 2017 Virgin Birth in SPACE!" (http://www.youtube.com/watch?v=v5dyEnZFu0w). It shows what happens immediately before the Revelation 12:1-2 sign. On November 20, 2016, Jupiter enters the womb of Virgo. It then moves toward the legs, but right before it crosses the line it reverses course making a loop (staying in the womb). Then it passes out of the womb on September 9, 2017, after 41 weeks (a normal gestation period). As Scott says, "what are the odds"?
After this, I was curious to know what happens in the next few years after the Revelation 12:1-2 sign. So I got a copy of Stellarium and checked. After the encounter with Mercury, Saturn moves into Sagittarius and stays there for about three years. Jupiter moves to Libra and then slowly moves toward Saturn. On December 16, 2020, Jupiter moves very close to Saturn and remains there for ten days. A few weeks later Jupiter, Saturn, and Mercury are close together near Capricorn. Then, on February 4, 2021, Saturn enters Capricorn and remains there for two years. Jupiter moves to Aquarius, stays there about a year, and then continues on. This could represent Satan indwelling the Antichrist until Jesus returns to wage war against him. Afterward, Michael throws Satan into the pit (represented here by Capricorn, evidently).
From September 23, 2017 (when the Revelation 12:1-2 sign occurs) until February 4, 2021 (when Saturn enters Capricorn) is almost 3.5 years. If these signs represent the second half of the Tribulation, then we must be very close to the beginning of the Tribulation and even closer to the Rapture. I don't know what the offset will be between the signs and the actual events, but surely the Rapture can only be a year or two away, at most.
If you want to get your own copy of Stellarium and check this out, go to http://www.stellarium.org. I have listed a timeline of the events below.
11/20/16 Jupiter enters the womb of Virgo
9/09/17 Jupiter leaves the womb of Virgo (after 41 weeks)
9/23/17 Revelation 12:1-2 sign
Saturn is between Serpens and Sagittarius. Mercury moves toward Saturn.
12/06/17 Saturn is near Sagittarius. Mercury passes close by.
Mercury moves away and then returns to Saturn.
1/13/18 Mercury passes close to Saturn a second time.
Saturn moves into Sagittarius. Jupiter is in Libra.
4/02/18 Mars passes close to Saturn.
Saturn stays in Sagittarius. Jupiter slowly moves toward Saturn.
As Jupiter gets closer to Saturn, Saturn backs away staying near Sagittarius.
3/20/20 Mars passes close to Jupiter.
3/31/20 Mars moves toward Saturn and passes near by.
12/16/20 Jupiter moves close Saturn and remains very close for 10 days.
1/09/21 Jupiter, Saturn, and Mercury are close together near Capricorn.
2/04/21 Saturn enters Capricorn and remains there for almost 2 years.
3/04/21 Jupiter and Mercury come together inside Capricorn.
4/19/21 Jupiter enters Aquarius.
8-12/21 Jupiter moves back to the tail of Capricorn and then returns to Aquarius.
2/25/22 Jupiter leaves Aquarius.
1/15/23 Saturn leaves Capricorn.