For the treatise on time written by Bede the Venerable, see The Reckoning of Time.
Contents
In the canon law of the Catholic Church, the computation of time, also translated as the reckoning of time (Latin: supputatio temporis), is the manner by which legally-specified periods of time are calculated according to the norm of the canons on the computation of time.
Months
Months are computed according to the calendar from the date of publication. A "canonical month" (in contradistinction to a "calendar month") is a period of 30 days, while a "calendar month" is a continuous month.
Vacatio legis
The vacatio legis is computed according to the calendar; for example, if a law is promulgated on 2 November, and the vacatio legis is 3 months, then the law takes effect on 2 February. So a universal law has a vacatio legis of approximately 90 days—3 months taken according to the calendar—while a particular law has a vacatio legis of approximately 30 days—1 month taken according to the calendar—unless specified to the contrary.
History
From 1918 to 1983, Book I, Title III of the 1917 Code of Canon Law regulated the computation of time in the Latin Church.