With some Israelites saying we should not keep the Feast days while in exile and some saying we should keep the Feast days while in exile, the most important question that should be asked is what does YHWH say according to his law?
Deut. 30:1-3 "And it shall come to pass, when all these things are come upon thee, the blessing and the curse, which I have set before thee, and thou shalt call them to mind among all the nations, whither YHWH thy ALHYM hath driven thee, and shalt return unto YHWH thy ALHYM, and shalt obey His Voice according to all that I command thee this day, thou and thy children, with all thine heart, and with all thy soul; That then YHWH thy ALHYM will turn thy captivity, and have compassion upon thee, and will return and gather thee from all the nations, whither YHWH thy ALHYM hath scattered thee."
YHWH is saying, if Israel is in bondage and while in bondage, they call to mind the blessings and the curses that YHWH has put before them and then they return to YHWH and obey his voice, ACCORDING TO ALL THAT YHWH COMMANDED THEM THAT DAY AT MT. SINAI, then YHWH will return and gather Israel from all the nations. So, the only way YHWH will return and gather Israel is if Israel does all that YHWH commanded them.
Deuteronomy 12:21” If the place which YHWH thy ALHYM hath chosen to put his name there be too far from thee, then thou shalt kill of thy herd and of thy flock, which YHWH hath given thee, as I have commanded thee, and thou shalt eat in thy gates whatsoever thy soul lusteth after."
Chapter 12:21 of Deuteronomy is the Law of the Central Sanctuary, yet YHWH says if Israel is too far from the place that he chose to put his name, that Israel should still do as they are commanded.
Passover in captivity
And the children of the captivity kept the passover upon the fourteenth day of the first month.
For the priests and the Levites were purified together, all of them were pure, and killed the passover for all the children of the captivity, and for their brethren the priests, and for themselves.
And the children of Israel, which were come again out of captivity, and all such as had separated themselves unto them from the filthiness of the heathen of the land, to seek YHWH ALHYM of Israel, did eat,
And kept the feast of unleavened bread seven days with joy: for YHWH had made them joyful, and turned the heart of the king of Assyria unto them, to strengthen their hands in the work of the house of ALHYM, the ALHYM of Israel.
Now when I was come home again, and my wife Anna was restored unto me, with my son Tobias, in the feast of Pentecost, which is the holy feast of the seven weeks, there was a good dinner prepared me, in the which I sat down to eat.
And when I saw abundance of meat, I said to my son, Go and bring what poor man soever thou shalt find out of our brethren, who is mindful of YHWH; and, lo, I tarry for thee.
CAN THE FEAST DAYS BE KEPT OUTSIDE OF JERUSALEM? Yes
It was on Mt. Sinai that the Creator gave Moses the dates and observances of the seven feast days. Being that the Creator's calendar begins with a new moon, these feast days would not fall on the same dates throughout the year as man-made holidays do every year. The only way we would know the appointed times to observe them was by looking for the sighting of the new moon. YHWH chose for his name to be in Jerusalem (2 Chronicles 6:6; 1 Kings 11:36) for out all the twelve tribes, this is the place YHWH chose to put his name (Deuteronomy 12:5). Therefore we should look to the sighting of the new moon in Jerusalem, for it is also stated that, YHWH made a covenant with the SEED of Abraham, Isaac and Jacob to give the land to the children of Israel FOREVER for an Inheritance (Gen 12:7,15:18, 17:7-8; Deut. 29:8) We do understand that we, the children of Israel, are currently scattered amongst the nations in the four corners of the earth (Deut. 28:64; Lev. 26:23; Jer. 9:16; Eze. 12:15). Yet, looking to the sighting of the new moon in your captivity is not the same since Jerusalem time zone is different than your captivity time zone. Yes, it is the same moon, but it is not the same time. In the first month (Abib) the sighting of the first fruits, which is barley, is what we are to look for along with the new moon sighting, so that we may know that the month of Abib has begun. This starts the beginning of the year for the Hebrew calendar. During the time of the plague of hail the barley and flax was said to be at their full size so this would be the first sighting of the first fruits, Exodus 9:31. The basic meaning of the word Abib is the stage in the growth of grain when the seeds have reached full size. Exodus 34:18, Leviticus 23:5 and Deuteronomy 16:1 gives the name of the first month (ABIB). The name of the month of Abib was changed to Nisan after the Babylonian captivity (Nehemiah 2:1) Abib/Nisan falls somewhere within the Gregorian calendar months March/April because this is the time that the first fruits began to be sighted.