The third commandment enjoins us to honor the Lord's Day and keep it holy. This command is part positive, part negative - positively, it commands us to worship God and devote this day to Him in a special way; in a negative sense, it prohibits us from engaging in certain activities that are traditionally referred to as "servile labor."
However, what exactly constitutes servile labor is usually not spelled out except in the most general terms. To a large extent Christianity has never adopted the Judaic practice of compiling exhaustive, definitive lists of exactly what is and is not prohibited (e.g., exactly how long one can travel in a day, what household items can be used and what can not, how much weight it is acceptable to lift, etc). Christianity, being a faith of the spirit and not of the letter, has tended to prefer very general guidelines, leaving the specifics to the (presumably well-formed) conscience of the individual and the customs of the times.
Just because Christian tradition has tended to leave much of this to the individual's conscience does not mean there are no guidelines at all. Before the modern age, Catholic catechisms featured very helpful, concise lists of activities generally considered inappropriate for Sundays and Holy Days. This sort of instruction has generally disappeared from catechetics and homiletics since the Council.
Protestants, of course, working from an exaggerated dichotomy between the "freedom of the Gospel" and "legalism" have generally eschewed any restrictions on Sunday activity whatsoever. Work of all sorts is usually accepted; Most Protestants I speak with on the subject consider the prohibition of any work whatsoever on Sunday to be a Jewish legalism. Protestants do not even believe going to church on Sunday is an obligation - in fact, I know Protestants who will occasionally stay home on Sunday morning intentionally just to prove that they have no obligation to attend to any communal worship on Sunday.
Of course, there is no obligation to attend Protestant worship; this applies only to the Catholic Mass, but we are speaking here only of principle. The point is that contemporary Christianity generally has very little sense of anything being unacceptable on Sunday, both among Catholics and Protestants.
Being Catholic, we have nothing to say about what Protestants choose to observe on Sunday; their unfortunate ubiquitous dualism between "works" and "freedom" is too radical for most to have a balanced approach to the question. But from a Catholic perspective, it would be helpful to return to the traditional concept of "servile labor."
Servile labor traditionally means any sort of work that is heavy manual labor, or such work as in a given society people commonly associate with strenuous effort and do not engage in when they have the freedom to avoid it; it is work you do "for a living", versus something you might engage in for recreation, education, or the worship of God. I want to share - in an informal way - some of my attitudes towards this aspect of Sunday and some rules of thumb I follow in assessing what is and is not "servile labor." This is all just my own approach; I don't claim it's authoritative in any way.
I personally apply the label "servile labor" to any sort of job or chore that is strenuous. For example, I would personally not work on a home improvement project on Sunday. Tiling the bathroom, shingling a roof, pruning trees - in my household, these sorts of projects are off limits on Sundays. Even if they are not "for a living", they are just too strenuous and physical for me to feel comfortable doing them on the Lord's Day. It seems incompatible with the concept of rest.
In the modern age, however, it is not as helpful to focus on the "manual" aspect of servile labor, because a great many people no longer engage in any sort of strenuous physical work. Rather, I find it more helpful to associate servile labor with that which you do "for a living" - i.e., your job. Thus whereas in the old days farmers were encouraged to abstain from farm work on Sundays, nowadays it is common for Catholic business people to abstain from phone conversations relating to business or looking at work emails on Sunday, even though these actions are not strenuous physically. Even so, I think this is a good modern adaptation of the principle. I avoid anything work related on Sunday.
What about strenuous physical sports? In this case, I think it is alright, because, say, getting all worked up and sweaty playing basketball is still clearly recreational - it is merely strenuous recreation, and I think that distinction is important. Now some will immediately say, "But what if it is recreational for me to tile my bathroom or hang siding on my house? Should that not be allowed by your criteria?" To that I say, "Friend, if you can truly tell me that the tiling of your bathroom or the siding of your house is truly and solely a recreational pursuit, then be my guest, I suppose." But I don't know anyone who undertakes a home improvement project just for fun and without any utilitarian reason.
In general, I avoid anything that seems like a "chore." I have mentioned home improvement sorts of projects; I also avoid more routine chores. Doing laundry. Chopping firewood. Mowing the lawn. Vacuuming the house. Washing the windows. Weeding the garden. Going grocery shopping. This also includes homework; my kids are forbidden from doing homework on Sundays, and I will not grade student homework on Sundays. Anything that is a "chore" we avoid.
However, we do make one exception - chores that have to do with simply maintaining basic sanitation and cleanliness are allowed. If the trash is overflowing, I will still take it out on Sunday. If the sink is full of dirty dishes, of course I wash them. I don't vacuum the house in general, but if the kids were eating popcorn and make a mess, of course I vacuum it up. So essentially anything that is like, maintaining basic sanitation and cleanliness we will do.
I will do other sorts of "work" that is recreational. I obviously blog on Sunday. I will spend time writing or working on books. I will exercise or do things for personal fulfillment.
I often get the question on whether or not it is alright to go out to eat on a Sunday. The objection is that when we go out to eat, we are forcing other people to work on Sunday (i.e., the waitstaff, cooks, etc. who staff the restaurant). I suppose this question comes up because it is so common for people to go out for breakfast after Mass that it is a very common quandary.
I personally have never objected to going out to eat on Sundays and Holy Days. Feasting is a way the Holy Day is celebrated, and often times Sunday is the only everyone in the family is home from work and able to go out together. It is celebratory. Now, it could always be argued that it causes the restaurant staff to work. Perhaps. I assume they would be working that day whether or not I came in to the restaurant. I also assume - generally - that people who are working on Sunday morning are not Catholics anyway, so I don't scrupulize too much over whether they are doing unnecessary work on Sunday. At any rate, the concern has never stopped me from enjoying breakfast with my family on a Sunday.
I do, however, try to support businesses that close on Sunday.
One final thing: even though the disappearance of a real catechesis about the Lord's Day is a post-Conciliar phenomenon (perhaps with the exception of St. John Paul II's Dies Domini
), do not be tempted to think that flaunting the prohibitions against work on the Lord's Day is something modern. As far back in history as one can find homilies, one can find examples of preaching against servile labor on Sundays. Even in the "golden age" of the 13th century, surviving homiletics reveal that working on Sundays and Holy Days was endemic; several chapters in the Fioretti
of St. Francis are devoted to describing the misfortunes of peasants who worked on Holy Days. It is certainly not a post-Vatican II novelty. So please, no comments about how in the "old days" no Catholic would have ever dared work on Sunday.
We also should remember, in the Middle Ages there were many more days that were considered Holy Days where work was prohibited - so many so that many common folk complained about not having enough time to finish their work. I cannot cite the source, but I remember reading in one scholarly work on medieval calendars that in some places as many as 100 days out of the year were nominally supposed to be work-free. This was, of course, excessive, and by the 13th century many of these days were no longer being observed. This cluster happened as a result of the accumulation of universal and regional festal days over the centuries; it was not until after Lateran IV and the reforms of the late Middle Ages that the status of many of these feasts changed to make their observance more manageable.
Anyhow, such are my hodge-podge of random thoughts on the duty to abstain from servile labor on Sundays. Any comments or thoughts are welcome. Pax.