In reply to your post called Second Mention of 631, God Narrows it Down? at http://www.fivedoves.com/letters/may2012/clay526-1.htm  Deuteronomy 16:16 lists the 3 required feasts as follows:

 

Deuteronomy 16:16, "Three times a year shall all thy males appear before the Lord thy God in the place which he shall choose; in the feast of unleavened bread, and in the feast of weeks, and in the feast of tabernacles: and they shall not appear before the Lord empty:"

 

The feast of weeks is also know as the feast of shavuot or Pentecost, and the feast of tabernacles is also called the feast of the ingathering.  All the males were required to go up to the temple in Jerusalem during the 3 required feasts.  At the rapture-resurrection, we would go up to New Jerusalem.

 

Exodus 23:14-17, "Three times thou shalt keep a feast unto me in the year.  Thou shalt keep the feast of unleavened bread: (thou shalt eat unleavened bread seven days, as I commanded thee, in the time appointed of the month Abib; for in it thou camest out from Egypt: and none shall appear before me empty:) And the feast of harvest, the firstfruits of thy labours, which thou hast sown in the field: and the feast of ingathering, [which is] in the end of the year, when thou hast gathered in thy labours out of the field. Three times in the year all thy males shall appear before the Lord GOD. "  (Abib is presently called Nisan.)