2578. Time and Place of Mass.—In reference to circumstances, the precept requires that Mass be heard at the proper place and the proper time.
(a) Place.—The precept may be complied with by attending Mass in any Catholic rite (Latin, Greek, etc.), and it makes no difference whether Mass is celebrated in the open air, in a church, or in a public or semi-public oratory (Canon 1249). But private chapels are for the benefit of the grantee alone.
(b) Time.—The precept must be complied with on the feast itself, that is, during the period of twenty-four hours from midnight to midnight. Sunday Mass cannot be anticipated on Saturday or put off till Monday. Likewise servile works are unlawful from midnight to midnight.
2579. Servile Works.—The prohibitory part of the precept is concerned with servile works, that is, labor of a kind that tends to make one unfit for devotion or that shows disrespect for the sacredness of the day, even though the labor be done gratis, or for recreation, or out of devotion. Hence, the law forbids:
(a) works given to the service of the devil, that is, sins that deprive one of holiness, such as riotous recreations, gambling, drunkenness, reading improper matter, and attendance at evil movie performances. But these works are opposed to the end, not to the text, of the law; and hence the circumstance of time aggravates their malice but does not give them a new species (see 2314);
(b) works given to the service of the body (servile works properly so called) or to the service of external goods (forensic and commercial works). Servile works in the strict sense cause bodily fatigue and are taken up with material things, and hence they distract the mind from religious thoughts. Such are manual labors (e.g., plowing, digging, housecleaning) and mechanical or industrial labors (e.g., printing, building, plastering, shoemaking). Forensic and commercial labors (e.g., arguing in court, auctioneering) are also of a very worldly kind and unsuitable for the quiet and recollection of Sundays and holydays.
2580. The prohibitory part of the Sunday precept does not affect works which are no impediment to devotion and which cast no dishonor on the day. Such are:
(a) works devoted immediately to the service of God. The purpose of the law is to allow leisure for these works, and hence manifestly their performance is not forbidden. Such works are saying Mass, preaching, administering the Sacraments, singing in church, and visiting the poor and sick (John, vii. 23; Matt., xii. 5). But works that are only remotely related to divine worship (e.g., cleaning the church, painting the altar, repairing the vestments, decorating the shrines) should not be done on Sunday without necessity;
(b) works devoted to the service of the mind (liberal works). These works are of a more elevated kind, do not require great bodily exertion, and are not looked upon as unsuitable to the Sabbath. Such are intellectual works (e.g., teaching, reading, writing, studying), artistic works (e.g., playing the organ, singing, drawing, painting a picture, embroidering), and works of recreation (moderate sports or diversions such as baseball, tennis, and chess).
2581. Other Kinds of Works and Sunday Observance.—(a) Common works are those that stand between the liberal and the servile, since they are exercised equally by mind and body, such as walking, riding, hunting, and fishing that is not very laborious. These are lawful.