TIME, COMPUTATION OF. — *De temporis supputatione* is a title, unknown in ancient canon law, introduced among the *Normae generales* of the CIC (tit. III, cann. 31-35) to provide general principles on the method of computing time in relation to legal prescriptions.
I. CANON LAW
The basis of 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 uniformly calculated as 30 days, and the year as 365, except in cases where months and years are taken according to their actual duration on the calendar (can. 32). The division of the hours of a day is measured in relation to solar time; and there is the *true time* determined by the passage of the sun over the same meridian and called *mean* within the space of 24 hours (can. 33 § 1); the *mean* determined by the arithmetic mean of true solar days, as if the sun always crossed a meridian line at exactly 24-hour intervals; the *ordinary legal time*, which is the conventional time on the same time zone, and the *extraordinary legal time*, which, under certain circumstances, adjusts the ordinary time for specific purposes that a State may establish. Time varies from place to place at the same moment. To regulate economic life, attempts were made to standardize variations through agreements among civil States (International Congress of Rome, 1884), dividing the world into 24 time zones or bands, each of 15 degrees starting from the meridian of Greenwich.Italy follows the 15th meridian of the time zone that passes through Mount Etna and more precisely through Termoli (Campobasso): consequently, true astronomical time is found only on 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 time shown on clocks, which is the official railway time. Thus, for the main Italian cities, there is a more or less significant interval, either ahead or behind, between legal time and true time.
II. TIME AND ITS DIVISIONS
Continuous time does not suffer interruptions, whereas interrupted time breaks its course, so that its total duration is merely the sum of the static days. When, in legal texts, a month is indicated by the name it has on the calendar, time is considered continuous, as in the case of February, which may have 28 or 29 days; but when the name is not given, time is considered interrupted, e.g., a month of vacation is the sum of 30 actual days of vacation, without regard to the duration of the month on the calendar. Legal jargon has emphasized the meaning of the expression *continuous*, contrasting it with *useful time*, depending on whether the law takes into account any impediment to action. Through artificial combinations, time may be useful at the beginning and continuous in its course if the law takes account of the impediment, after which time resumes its continuous course until its expiration; or the endpoint may be extended if it falls on a holiday, i.e., a day on which no action can be taken; or its course may be suspended, resuming once the suspension ceases (can. 35).Useful time is also the period that the law grants for the fulfillment of an obligation (cf. can. 859 § 2), which may be satisfied at any moment within the time limits (beginning and end) set by the law itself. Thus, one who is bound to recite the Divine Office may do so at any moment within the 24 hours of the day, after which the obligation for that day ceases and that of the following day begins (can. 33 § 1); in such a case, it is said that the time was assigned “to fulfill the obligation.” At other times, however, the obligation continues even after the fixed term has passed: e.g., the time for Easter is the so-called paschal time. If one does not receive Holy Communion within the established time, he indeed fails in his obligation, but the precept of communicating at least once a year remains and does not cease until the time for the following year begins. In such a case, it is said that the time was assigned “to remove the obligation” (can. 859 § 4). It should be noted that, according to the CIC, the expressions “every third, fifth, tenth, twentieth year” 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 proper names or in an unequivocal manner extends throughout the entire duration of those years and months, even though the duration of individual years and months is not always identical. In the computation of the hours of a day, one must follow the clock, which, as a rule, is regulated according to the time of the time zone. However, for acts of private religious life, the faithful are permitted to follow at will true or mean astronomical time, the legal time of the time zone, or the extraordinary legal time in force at the place. It is debated among canonists whether the enumeration of acts of private religious life contained in can. 33 § 1 is exhaustive or merely illustrative. Evident reasons of analogy, with the intent of favoring freedom, suggest that the interpretation which considers the enumeration merely illustrative is more in keeping with the mind of the legislator and the purpose of the law. It is also permissible to vary the choice of computation for different acts, unless the simultaneous use of different computations results in the violation of one of two laws that coincide in the case. E.g., if someone, on Friday, adhering to legal time when the clock has already struck midnight, were to eat meat, he would not violate the law of abstinence; but the next day he could not receive Holy Communion, even under the pretext that midnight had not yet arrived when he ate. Indeed, such a person would either violate the law of abstinence or the law of Eucharistic fast. On this point, however, the most recent apostolic provisions (6 Jan. 1953) should be taken into account.
2. COMPUTATION OF TIME
Natural computation proceeds mathematically “from moment to moment” (D. IV, 4, 3 § 3). If the period must be continuous, the calendar is followed strictly. If, however, the period is interrupted, a week extends for 7 full days, a month for 30, and a year for 365, unless the legal text assigns the starting point of the time and this falls at the beginning of the day, in which case the starting point is counted, but the endpoint is not; e.g., a month’s vacation from 15 January ends at midnight before 15 February; fifteen days beginning on 10 January end at midnight on 14 January. But if the starting point does not fall at the beginning of the day, but during the course of the day, it is not counted: e.g., in the ten fatal days granted for appeals or petitions 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 entire month as it is taken on the calendar, thus 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, i.e., after 28 or 29 days.For the renewal of specific acts with a fixed deadline, no solution of continuity is permitted, and the renewal must take place on the exact date of the previous act: a temporary profession made for one year on 10 August must be renewed on 10 August 1953, at any moment of the day, from midnight to midnight (can. 34). Can. 33 § 2 canonizes territorial civil law regarding the expiration of contracts, in conventional obligations, whether principal or accessory, in the accrual of default interest, damages, and risks arising from non-performance. Even the terms of a moratorium possibly granted to debtors by civil courts may be applied in canon law, in accordance with the general principle enunciated in can. 1529.