it was a command for the nation of Israel only. it was never commanded for gentiles. we are to take a day of rest, as God the father instituted in the Creation, but non-jews were never under the Sabbath command.
I almost hesitate to enter the discussion because I do not want to get into arguments, but, hey, I've got a big mouth.
I had an aunt who was devotedly a Seventh-Day adventist and she invited me to church several times ( and I, with my family, accepted). I am one that has no problems with and I respect other's interpretation of the Scriptures because I would expect that over 2,000 years man's confusion would naturally result in diverse beliefs; but the day that I heard the preacher say that if you don't worship on Saturday, you're going to hell - I never returned. It was a number of years ago, and I might be a little fuzzy on his exact words, but that was definitely the impression I left with on that day.
I don't agree, and we worship on Sunday - yes, and rest. I've long known that a nap on Sunday afternoon lends a great deal of energy to my body the entire week. Besides, as I told my aunt, when Adam and Eve were created, God did not drop a calendar in the garden for them to keep track. How does anyone know for sure that humans have gotten confused over the dates in all of history - especially in the beginning? I mean, I think of all the times (ok - don't laugh) I've gone through entire days only to find out it's not the day I thought it was (ex: it was Wednesday, not Tuesday like I had thought) (ok, go ahead and laugh).
Just my opinion. Also, my knowledge that God is not a God of the law, but a loving caring creator. We've set aside a day consecrated to him and rest in his glory. My Lord and Saviour is more concerned with our hearts and the intent of our hearts. God bless you all!