I am a SDA (No not the pagan type). I would agree that no specific day is mentioned (Saturday or Sunday or any other weekday at that) as being the Sabbath. But I would say that the Jewish Calendar is the most accurate calendar that goes hand in hand with the Bible. The calendar we use today although days were added do to the selfishness of Roman Emporers wanted more days that previous emporers, it still is the same as the jewish calendar as per the days of the week. I would stick to God's Moral Law the 10 Commandments as they were not abolished since Sin is the Trangression of God's Law. We would not know sin if it were not for God's law. God had to re-instruct the Jews on the Sabbath since they were enslaved by the Egyptians for so long that they were unaware of God's laws. He gave them Manna from heaven and on the Sixth day he gave them double so that they would not have to go and collect any on the Sabbath (7th Day). I would say that the Jewish Calendar would be correct to the Day that God had not given them Manna and showed which day was the Sabbath. The Sabbath was created for Man not Man for the Sabbath. Hence The Sabbath was created for Man not Jew.
The wages of sin is death: we are all subject to the earthly consequences of sin. Being a christian does not make us immune to hardship or pain. Being a christian means we recognize that God is with us in our pain, and He has promised that ALL things work together for good.