I've seen conflicting theories about whether Noah's flood and the 17th day of the 2nd month was from the fall or spring calendar. Jesus said He will come "as in the days of Noah" 

Passover, Unleavened Bread, and Firstfruits occur from April 15-22nd

What's notable is that there is a total lunar eclipse, aka blood moon on May 15th. Bible says the sun will be turned to blackness and the moon to blood before the Great and Terrible day of the Lord comes. May 15th is 30 days after first Passover and would be second Passover:

“Tell the Israelites: ‘When any of you or your descendants are unclean because of a dead body or are away on a journey, they are still to celebrate the LORD’s Passover, but they are to do it on the fourteenth day of the second month at twilight. They are to eat the lamb, together with unleavened bread and bitter herbs." Numbers 9:10,11

If we are here on earth away from heaven, we are on a far journey. The touching of a dead body could be Jesus somehow--who of course is now risen. That would place this year's 2nd Passover right at the Blood Moon May 15th, which is the 2nd month 14th day. I've heard prophetic words about a 3 day warning or 3 days of darkness which could take us to the 2nd month 17 days. Also Nathan's death vision occurred at Sukkot in 2015 which is 7 years from this fall and rapidly approaching.

I believe there is a connection with 47 (30 + 17   we read later in scripture that 150 days = 5 months which is a 30 day month) days of Noah, and 47 days of Moses on the Mt, but not sure how that fits together right now.

The spring rapture also aligns with the Song of Solomon so this upcoming Passover could be very interesting.

Steve M