In America, a society of Gentiles, we usually hold ourselves to a double-standard on Sunday, the so-called Sabbath. Most people don't work, but this is not because we have some kind of unwavering devotion to a special day of rest. It's because many of the businesses we work for are closed on Sundays. So out of convenience and not religious fervor, we take advantage of the day off, worshiping in the morning, eating lunch and then curling up on the couch for an afternoon nap.
I'm not condemning this routine. I just think it's funny how we profess to be observing the Sabbath, but we bypass its restrictions if they become inconvenient for us. We, a Gentile people, have taken a Jewish custom (which by the way would've been celebrated on Saturday) and Americanized it, changing it from a time of reflection on God's goodness to an excuse to watch football. We want it both ways. We subject ourselves to some aspects of the Old Testament law, but we also dismiss some as culturally obsolete. In order to decide on matters such as these, I like to take Paul's advice in Romans 14 (and the book of Galatians), where he addresses the differences between Jew and Gentile and the extent to which Gentiles should be held accountable to Jewish customs:
One man considers one day more sacred than another; another man considers every day alike. Each one should be fully convinced in his own mind. He who regards one day as special, does so to the Lord (Romans 14:5-6a).
The predominate theme of the chapter is clean and unclean food and how abstaining or partaking affects the faith of the one eating and those around him. Paul uses this subject to expound upon our freedom in the faith, and how freedom runs out at the same time peace starts to disappear. As Paul says, Let us therefore make every effort to do what leads to peace and to mutual edification (Romans 14:19).
This passage does not serve as a license for us to do whatever we want as long as it leads ultimately to peace. Doing the right thing often requires us to go against the consensus viewpoint (think Jesus turning over tables in the temple). What Paul is doing here is making sure that we don't harbor narrow views that unnecessarily limit our faith. If God has declared all foods clean, we should not hesitate to eat them. But if we some not yet strong enough to do so, Paul says that those with stronger faith should bear with them.
Similarly, if some of us regard the Sundays as worship/football day and others see it as a day to put in some extra hours at the office, we should all be able to get along, providing that we all agree that we must meet together with God's people and we must set aside time to worship him during the week. In all things, his purposes are to be held in the highest regard, and we should always seek to interpret the law with faith, not legalism, as our motivation.