As God has expressed that He declares the end from the beginning, I am thinking that to understand our "end" down here, in terms of when Jesus comes for us, we have to go back to the beginning. I am thinking here of the circumstances of Adam getting his bride as a picture of Jesus getting His. 

Why did Jesus do "40 days" that ended at His second ascension? Per Leviticus 12, I am thinking He was required to. A clue is in the non-canonical Book of the Jubilees chapter 3, which does not contradict scripture. 

When Adam was created, he was complete in his "humaness", embodying masculine and feminine. In providing Adam with a companion, God removed not only his rib, but his feminine aspect as well in order to give him Eve. The former, what I have nicknamed, "combo Adam" no longer existed. After Eve was brought into existence, it then was in the "union of the two" to make "the one". "Adam masculine" and "Eve feminine" were both essentially birthed out of "combo Adam". 

So, per Leviticus 12, Adam had to wait 40 days before he could go back into the garden to enjoy walking with and interacting with God. Eve had to wait 80 days, or (and this is key) 40 more days AFTER Adam entered. 

Jesus, like Adam, entered into a deep sleep. During His "sleep" His side was opened like what happened to Adam. When Jesus "woke up", who did He meet first? According to the gospel of John, it was Mary! The first member of His bride. 

Earlier that morning, Mary had found the stone rolled away and left to tell the others. Peter and John came, looked into the empty tomb, and walked away. Mary then looked in. When she did, she saw two angels on either side of the linen wrap "sprinkled" with the blood of the new covenant. This echoes the ark of the covenant in the temple, and is also a picture of the throne in heavenly places. By being in the tomb, Mary is identifying with Jesus in His death and burial, just like us as new creations in Christ Jesus.  She then turns from looking in the tomb and sees Jesus. Here, she is picturing the brides' identification also with Jesus in His resurrection. The result?  

She is in Jesus' presence. Only Mary went through this! Only Mary saw Jesus before He ascended the first time! Not Peter. Not John. Only Mary. This is huge. 

Recall that once "combo Adam" was "split" into Adam and Eve, "combo Adam" was no longer manefested as singular, but as a "two", masculine-Adam and feminine-Eve. I am thinking Jesus, in a way, did the very same thing. In other words, there is a masculine portion of the body of Christ (made up of men and women), and there is a feminine portion (also made up of men and women). 

At this point I need to be very clear about something: Jesus, as the great I AM, also transcends His manefestation as the "masculine Adam" aspect/portion of the body of Christ and the "feminine Eve" aspect/portion of the body of Christ. He is not limited by this.  This is a way He is going to reveal Himself to those of mankind who are not part of the Body of Christ as new creations. Jesus will be experienced by others, who are not part of the entire "new creations" group, in their interactions with "Adam and Eve", the "two" who are the manifestation of the One (Jesus).

When the rapture happens, all of those who have embraced Jesus at that point will be taken. I am thinking this is the masculine aspect of Jesus' body.  They have chosen to relate to Jesus directly as their "Head" now.  However, I am thinking, at the moment of the rapture, there are a large number of folks who will not have partaken of the tree of Life yet, but were seduced by the evil one like Eve was. After the initial rapture, they will then come into saving faith, but they will have to do their additional 40 days.  This group that will make up the Eve aspect of the body of Christ where, like the group that makes up the Adam aspect of the body of Christ, were chosen "in Him" BEFORE the foundation of the world.  In other words, when any of us choose Christ during our earth-lifetimes, it was only because He chose us.  Grace. 

However, because the Eve-group had not been relating previously to Jesus as their "Head" prior to the rapture of the Adam-group, they will end up relating to Jesus through their head, the Adam-group.

Now, recall that Jesus is the head of the man, and the man is the head of the woman. So, some of the previously raptured masculine group will come back down for 40 days (repeating what Jesus did), and guide and teach and even protect the feminine group during her additional 40 days. After her additional 40 days are done, then all are home at that point. I am thinking, with respect to the calendar, that this will be the day after Tisha B Av per the popular jewish calendar, AND it will be the final day of Shavuot per the Spica-Abib calendar.  The two loaves of bread made from one batch of dough symbolize, on one level, the Adam and Eve of the entire body of Christ.

Now keep in mind that because of the Adam-group's and the Eve-group's union with Christ Jesus, all of us have already done 40 days "in Christ". If we embrace Jesus now, before the rapture, we are choosing Jesus as our Head. These are the Adam-group. We will, in turn, serve in  headship-role to those of the feminine Eve group who as of right now have rejected relating to Jesus as their head. This will include a portion of the Adam-group coming back down to guide the Eve-group during her last 40 days.

In terms of the Gregorian calendar, I am thinking the Adam group goes up on July 4th.  The Eve-group will be taken into heavenly places at the end of her additional 40 days on about August 12th.

I hope I am clear. It is not simple, what I am trying to convey. 

Eve's extra 40 days is the same window of time as Moses' 40 days, as Noah's 40 days, and as Jonah's 40 days.  They all start on the 4th of July, the day Babylon's 70 years are up, and they all end the day after Tisha B Av on the jewish calendar this year.