COMPUTATION OF TIME. - De temporis supputatione is a title, unknown in ancient canon law, introduced among the Normae generales of the CIC (tit. III, cann. 31-35) in order to set out the general principles on how to compute time in relation to legal prescriptions.
I. CANON LAW
The basis of the computation is the Gregorian calendar. 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 for the duration they have on the calendar (can. 32). The passage of the hours of a day is measured in relation to the solar day; and there is true time, determined by the passage of the sun over the same meridian, and mean time, so called, within the space of 24 hours (can. 33 § 1); mean time is determined by the arithmetic mean of the true solar days, as if the sun always cut the line of a meridian at exactly 24 hours' distance; ordinary legal time, which is the conventional time of the same time zone, and extraordinary legal time, which under certain circumstances adjusts the ordinary time for specific purposes that a State sets for itself. Time varies from one place to another at the same moment. To regulate economic life, an attempt was made to fix the variations by agreements among civilized States (International Congress of Rome, 1884), dividing the world into 24 time zones, each of 15 degrees starting from the meridian of Greenwich.
Italy follows the 15th meridian of the time zone, which passes over Etna and more precisely over Termoli (Campobasso): consequently, true astronomical time exists only on the line of the 15th meridian; the rest of Italy, to the right or left of the meridian, has true time ahead of or behind the hour shown on clocks, which is the official railway time. Thus for the principal Italian cities there is a more or less wide interval, ahead of or behind, between legal time and true time.
1. Time and its divisions
Continuous time suffers no interruptions, whereas interrupted time breaks its course, so that its total duration is only the sum of the separate days. When in legal texts a month is indicated by the name it has in the calendar, the time is considered continuous, e.g., the month of February, which may have 28 or 29 days; but when its name is not indicated, it is considered interrupted, e.g., a month of vacation is the sum of 30 actual days of vacation, without taking into account the duration of the month in the calendar. Legal jargon has accentuated the meaning of the expression "continuous," setting it in opposition to useful time, according to whether or not the law takes account of any impediment to acting. By force of artificial combinations, time can be useful at the beginning and continuous in its course, if the law takes account of the impediment, once which has ceased the time resumes running continuously until its extinction; or it can postpone the endpoint, if this falls on a non-working day, that is, a day on which one cannot act; or it suspends its course, resuming once the suspension has ceased (can. 35).
The period that the law grants for the fulfillment of an obligation is also useful time (cf. can. 859 § 2), which can be satisfied at any moment within the terms (beginning and end) assigned by the law itself. Thus one who is obliged to it can recite the Divine Office at any moment of the 24 hours of the day, after which 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 had been assigned "ad finiendam obligationem." At other times, however, the obligation continues even after the fixed term has passed: e.g., the time for making Easter duty is the so-called Easter time: if one does not receive Holy Communion within the established time, he indeed fails in the obligation, but the precept of communicating at least once a year persists for him and does not cease until the time for the following year begins. In this case it is said that the time had been 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, 20 years, whereas classically they would mean every 2, 4, 9, 19 years.
The computation of years and months designated by their own name or in an unequivocal manner extends for the entire duration of those years and those months, however much the duration of individual years and individual months is not always identical. In computing the hours of a day one must go by the clock, which, as a rule, is set to the legal time of the time zone. Nevertheless, for acts of private religious life the faithful may freely follow true or mean astronomical time, the legal time of the time zone, or the extraordinary legal time in force in the place. It is disputed among canonists whether the enumeration of acts of private religious life contained in can. 33 § 1 is exhaustive or illustrative. Evident reasons of analogy, with the intent of favoring liberty, make it seem more consonant with the mind of the legislator and the purpose of the law to hold the interpretation that considers that enumeration merely illustrative. It is also permissible to vary the choice of computation for different acts, unless the simultaneous use of different computations results in violating one of two laws that coincide in the case. E.g., if someone, on a Friday, adhering to the legal computation, when the clock has already struck midnight wished to eat meat, he would not fail against the law of abstinence; but the next day he could not receive Holy Communion, not even under the pretext that true midnight had not yet come when he took food; in fact, such a person would either violate the law of abstinence or violate the law of the eucharistic fast. But in this regard one should keep in mind the very recent apostolic provisions (Jan. 6, 1953).
2. Computation of time
Natural computation proceeds mathematically "de momento ad momentum" (D. IV, 4, 3 § 3). If the period must be continuous, the calendar is followed rigorously. If instead the period is interrupted, a week extends for 7 whole days, a month for 30, and a year for 365; if, however, the legal text assigns the starting point of the time and this falls at the beginning of the day, the starting point is counted, but the endpoint is not counted; e.g., a month of vacation from Jan. 15 ends at the midnight preceding Feb. 15; fifteen days beginning from Jan. 1 terminate at midnight of Jan. 14. But if the starting point does not fall at the beginning, but rather in the course of the day, this is not counted: e.g., in the fatal ten days granted for appeals or recourses against sentences or procedural decrees, the day of notification is not counted. Finally, if the assigned time coincides with the current month, it extends for the whole month, as this is taken in the calendar, therefore of 28, 29, 30, or 31 days. This also occurs when the endpoint does not correspond with the starting point: a suspension for one month beginning from Jan. 31 ends at the expiration of the following February, that is, after 28 or 29 days.
For the renewal of specific acts at a fixed expiration, no interruption is admitted and the renewal must be made on the precise date of the previous act: temporary profession made for one year on Aug. 10, 1952 must be renewed on Aug. 10, 1953, at any moment of the day, from midnight to midnight (can. 34). Can. 33 § 2 sanctions territorial civil law in matters of contract expirations, in conventional obligations, principal or accessory, in the running of interest for delay, of damages and of risks arising from non-fulfillment. Even the terms of a moratorium possibly granted to debtors by the civil judge can find application in canon law, and this in application of the general principle enunciated by can. 1529.
II. LITURGICAL LAW
Liturgical law follows a different order of ideas in the computation of time (cann. 2, 31); in the Missal and the Breviary time is lunar, not solar; the day is computed from first Vespers until the twilight of the following day. A different computation of time likewise governs the law of indulgences (cann. 921 § 3, 922, 923).
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Agostino Pugliese