In Roman antiquities, fasti is the plural of the Latin adjective fastus, but more commonly used as a substantive, derived from fas, meaning what is binding, or allowable, by divine law, as opposed to jus, or human law. Fasti dies thus came to mean the days on which law business might be transacted without impiety, corresponding to our own lawful days; the opposite of the dies fasti were the dies nefasti, on which, on various religious grounds, the courts could not sit. The word fasti itself then came to be used to denote lists or registers of various kinds, and especially those that had to do with keeping or marking time.
Upon the cultivators fewer feasts, sacrifices, ceremonies and holidays were enjoined than on the inhabitants of cities; and the rustic fasti contained little more than the ceremonies of the calends, nones and ides, the fairs, signs of zodiac, increase and decrease of the days, the tutelary gods of each month, and certain directions for rustic labors to be performed each month.
The word fasti thus came to be used in the general sense of annals or historical records. A famous specimen of the same class are the fasti Capitolini, so called because they were deposited in the Capitol by Alexander Farnese, after their excavation from the Roman forum in 1547. They are chiefly a nominal list of statesmen, victories, triumphs, &c., from the expulsion of the kings to the death of Augustus. A considerable number of fasti of the first class have also been discovered; but none of them appear to be older than the time of Augustus. The Praenestine calendar, discovered in 1770, arranged by the famous grammarian Verrius Flaccus, contains the months of January, March, April, and December, and a portion of February. The tablets give an account of festivals, as also of the triumphs of Augustus and Tiberius. There are still two complete calendars in existence, an official list by Furius Dionysius Philocalus (354), and a Christian version of the official calendar, made by Polemius Silvius (448). But some kinds of fasti included under the second general head were, from the very beginning, written for publication. The Annales Pontificum different from the calendaria properly so called were annually exhibited in public on a white table, on which the memorable events of the year, with special mention of the prodigies, were set down in the briefest possible manner. Any one was allowed to copy them. Like the pontifices, the augurs also had their books, libri augurales. In fact, all the state offices had their fasti corresponding in character to the consular fasti named above.
Apart from occasional uses of the terminology in other contexts (especially the word nefast remains, but generalized from a taboo to anything with grave negative consequences) the word fasti, or a translation (e.g. fastes in French, still a plurale tantum) has been used for more modern writings, such as the (official, treasured) history and traditions of a regiment (e.g. in Belgium). The word is also used in Scotland for a publication listing the biographies of clergy of a particular denomination: most famously, Fasti Ecclesiae Scoticanae: the succession of ministers in the Church of Scotland from the reformation, the first volume of which was produced by Hew Scott in 1915 and which is still updated at irregular intervals.
Between 1946 and 1987 the International Association for Classical Archaeology (AIAC) published the Fasti Archaeologici. It contained very useful summary notices of excavations through the area of the Roman Empire. It has now been moved to a web-based version, designed by L - P : Archaeology which can be found at Fasti_online