I will suggest thaqt this is one of those issues that is between us and the leading of God.
The reason I'm concerned about this issue is because it has been handed down from the church leadership in the Pacific Islands. It is not simply a personal issue between individuals and God.
There are many people in the Islands of Samoa who are basically locked out of the Seventh-day Adventist Churches. They are not allowed to worship in the Seventh-day Adventist Churches on Saturday. So they have been finding other places to worship. (Often outside) In other words -- those who believe the seventh day is from Friday sunset to Saturday sunset according to scripture are no longer treated like members of the Seventh-day Adventist Church.
Yes, I agree the established IDL is the guide as to where the new day begins.
So why do Adventists NOT accept the established IDL?
A one time "cross over" did not change the week. That cross over will soon be forgotten by everyone.
The day after their so called Sabbath is MONDAY in all that Monday means. Saturday they go play baseball or basketball, it's still considered the "weekend" but now Saturday is like any secular person regards a Saturday -- The week hasn't changed, but the Seventh-day Adventist churches now close on Saturday and open on Sunday right along with the Catholics, the Methodists and other denominations.
But to bring in a new prespective -- let's consider Tonga (a group of Island just south of Samoa)
Tonga has from the earliest introduction of Christianity about 100 years before Adventist missions arrived, held Sunday as Sunday in the eastern hemisphere. Tongan politics was pretty much influenced by the Weslyan missionaries who were into the politics as well as religion. The Weslyans and Catholics, and British Missionaries all kept Sunday -- the same as most protestants and all Catholics in Australia and New Zealand.
There has been NO IDL change in Tonga in all those years. Protestant and Catholic missionaries arrived in Tonga and kept Sunday according to the Eastern Hemisphere. Nearly 100 years later Adventists arrived from America and kept Sunday right with them, claiming it was really Saturday, and are still doing so today.
Tonga set the precedent -- and slowly the Islands are all being led into Sunday worship, simply because Adventists refuse to acknowledge that the IDL is set by the Island groups not by an arbitrary line that isn't taught by scripture or set by governments.
When Sunday laws come to America how are people in America who support Sunday keeping in these Islands going to answer?
If the authority of the Seventh-day Adventist Church can call Sunday the Sabbath and enforce it on their members in one area, why not listen to the authority of Protestant and Catholic call for UNITY against evil and uphold Sunday as the Sabbath to bring people back to God in America?