He does so for our own good. Christians have traditionally observed a day of rest and the ritual celebration of the Resurrection on Sunday, which is the first day of the week. In the past, many states sought to help create an environment conducive to Sunday rest by passing laws that forbade businesses from operating on Sundays. When I lived in Rome just over a decade ago, I quickly learned that if one needed to pick up anything at a drug store, one was well-advised to do so before lunchtime on Saturday. Today, it is very easy for us to treat Sunday like another Saturday--a day to go shopping, dine out, have sporting events for children, do yard work, and the like.
We must first recognize that some people have to work on Sundays. Those who work for churches, hospitals, and first responders are good examples. As a rule, however, most of the time most people are able to take a twenty-four break from paid work and servile labor if they have the mind to do so on Sunday. Those who must work on Sundays can almost always find another day to consecrate to the Lord for rest. I typically begin my day of rest on Thursday around noon and close it out in the twenty four hours later on Friday.
The most important element of Sunday rest is our involvement in Sunday worship. Involvement in Sunday worship is far more than just going to Mass every Sunday! It should also mean pulling one's weight by involving oneself in the ministries necessary for Sunday worship like proclaiming the readings, singing in the choir, serving as an usher, serving at the altar, greeting, counting the collection, and everything else in between. At the very least, one should attend Mass, which involves arriving in time to hear the beginning of the entrance song and stay until the priest or deacon says, "Go in peace." I invite those who habitually arrive late and leave early to examine their consciences as to whether they are in fact fulfilling their Sunday obligation to attend Mass.
But, what is one to do with the rest of the day? If doctors who have studied the sleep habits of Americans are correct, most of us would do well to get some extra sleep by taking a siesta. Making time for quality connections with God and neighbor are obvious ways to spend the rest of the day. Some of my fondest memories before ordination involve things done on Sundays: dinners accompanied by free-wheeling but usually respectful conversation among my family as an adolescent, coffee with friends along with extra time for prayer as a student, and so on. In our digital age, it may be a salutary exercise to limit or even eliminate entirely electronic media on Sundays in order to facilitate true Sunday rest.