TEMPO, COMPUTO del. — De temporis supputatione is a title unknown in ancient canon law, introduced among the Normae generales of the CIC (title III, canons 31–35) in order to provide the general principles governing the computation of time in relation to legal prescriptions.
I. CANON LAW
The Gregorian calendar is the basis of reckoning. The day is divided into 24 hours, from one midnight to the next; the week consists of 7 days; the month is calculated uniformly as 30 days, and the year as 365, except in cases where months and years are taken according to their calendar duration (can. 32). The passage of the hours of a day is measured in relation to the solar day; thus there is true time, determined by the passage of the sun across the same meridian, and mean time, calculated within the space of 24 hours (can. 33 § 1); mean time is determined by the arithmetic average of true solar days, as though the sun always crossed the line of a meridian at exactly 24-hour intervals; ordinary legal time is the conventional time within the same time zone, while extraordinary legal time adjusts the ordinary time in particular circumstances, for specific purposes established by a State. Time varies from one place to another at the same moment. In order to regulate economic life, efforts were made, through agreements among civilized States (the International Congress of Rome of 1884), to establish these variations by dividing the world into 24 time zones, or belts, each of 15 degrees, starting from the Greenwich meridian.Italy follows the 15th meridian of the time zone that crosses Etna and, more precisely, Termoli (Campobasso): consequently, true astronomical time occurs only along the line of the 15th meridian; the rest of Italy, to the right or left of the meridian, has true time either ahead of or behind the hour shown on clocks, which is the official railway time. Thus, for the principal Italian cities there is a greater or lesser interval, ahead of or behind, between legal time and true time.
1. Time and its divisions
Continuous time admits no interruptions, whereas interrupted time breaks its course, so that its total duration is merely the sum of the separate days. When, in legal texts, a month is designated by the name it has in the calendar, time is considered continuous—for example, the month of February, which may have 28 or 29 days; but when its name is not given, it is considered interrupted—for example, a month of vacation is the sum of 30 actual vacation days, without regard to the length of the month in the calendar. Legal terminology has accentuated the meaning of the expression « continuous », placing it in opposition to useful time, according to whether or not the law takes account of any impediment to acting. By virtue of artificial combinations, time may be useful in principle and continuous in its course, if the law takes account of the impediment, after which has ceased time resumes its continuous course until it expires; or it may defer the terminating point if this falls on a holiday, that is, a day on which action cannot be taken; or it may suspend its course, resuming it once the suspension has ended (can. 35).The period granted by law for the performance of an obligation is also useful time (cf. can. 859 § 2), since the obligation may be fulfilled at any moment within the limits (beginning and end) assigned by the law itself. Thus, a person bound to do so may recite the Divine Office at any time during the 24 hours of the day; once that period has elapsed, the obligation ceases for that day and that of the following day begins (can. 33 § 1). In this case it is said that the time was assigned « ad finiendam obligationem ». At other times, however, the obligation continues even after the fixed period has elapsed: for example, the time for fulfilling the Easter duty is the so-called Easter time; if someone does not receive Holy Communion within the established period, he certainly fails in the obligation, but the precept to receive Communion at least once a year continues for him and does not cease until the time for the following year begins. In this case it is said that the time was assigned « ad urgendam obligationem » (can. 859 § 4). It should be noted that, according to the CIC, the expressions « tertio, quinto, decimo, vigesimo quoque anno » mean: every 3, 5, 10, or 20 years, whereas classically they would mean every 2, 4, 9, or 19 years.
The reckoning of years and months designated by their proper name or in an unequivocal manner extends throughout the whole duration of those years and months, even though the duration of individual years and individual months is not always identical. In reckoning the hours of a day, one must follow the clock, which, as a rule, is regulated according to the legal time of the time zone. Nevertheless, for acts of private religious life, the faithful may choose freely to follow true or mean astronomical time, the legal time of the time zone, or the extraordinary legal time in force at the place. Canonists dispute whether the enumeration of acts of private religious life contained in can. 33 § 1 is exhaustive or illustrative. Evident considerations of analogy, with the aim of favoring freedom, make the interpretation that regards this enumeration as merely illustrative more consonant with the mind of the legislator and the purpose of the law. It is also lawful to vary the choice of reckoning for different acts, unless the simultaneous use of different reckonings results in violating one of two laws that coincide in the case. For example, if on a Friday someone, adhering to legal reckoning, wished to eat meat once the clock had already struck midnight, he would not violate the law of abstinence; but the following day he could not receive Holy Communion, not even on the pretext that true midnight had not yet arrived when he took food; in fact, he would either violate the law of abstinence or violate the law of the Eucharistic fast. In this regard, however, the most recent apostolic provisions should be kept in mind (6 January 1953).
2. Reckoning of time
Natural reckoning proceeds mathematically « de momento ad momentum » (D. IV, 4, 3 § 3). If the period must be continuous, the calendar is followed strictly. If, instead, the period is interrupted, a week extends over 7 complete days, a month over 30, and a year over 365; if, however, the legal text assigns the starting point of the period and this falls at the beginning of the day, the starting point is counted, but the endpoint is not counted. For example, a month of vacation beginning on 15 January ends at the midnight preceding 15 February; fifteen days beginning on 1 January end at midnight on 14 January. But if the starting point does not fall at the beginning, but during the course of the day, that day is not counted: for example, among the fatal ten-day periods granted for appeals or recourses against judicial sentences or decrees, the day of notification is not counted. Finally, if the time assigned coincides with the month in progress, it extends through the whole month as it is reckoned in the calendar, and thus comprises 28, 29, 30, or 31 days. This also occurs when the endpoint does not correspond to the starting point: a suspension for one month beginning on 31 January ends at the expiration of the following February, that is, after 28 or 29 days.For the renewal of specific acts with a fixed expiration date, no interruption is admitted, and the renewal must take place on the precise date of the preceding act: temporary profession made for one year on 10 August 1952 must be renewed on 10 August 1953, at any time
during the day, from midnight to midnight (can. 34). Canon 33 § 2 canonizes territorial civil law with regard to the expiration of contracts, conventional obligations, whether principal or accessory, and the accrual of interest on arrears, damages, and risks arising from non-performance. Even the periods of a moratorium possibly granted to debtors by a civil judge may be applied in canon law, in implementation of the general principle enunciated by can. 1529.