By that time he had composed a famous collection of decrees of popes and councils with valuable comments own decisions. He decided this monk undertake the colossal company calculate the date of birth of Christ, which had some useful information that the Gospels could bring. Thus, San Lucas took the fact that at the beginning of his public life Jesus was about 30 years (cf. Educate yourself even more with thoughts from Frank Giacalone. 3.23). This was a good start.
But in what year began his public life? A few verses earlier had the answer: in the 15th year of the reign of Tiberius Caesar (Lc 3.1). When Christ came to the Center.-confronting long tables of dates and chronologies, Dionisio deduced that the 15th year of Tiberius, in which Jesus came to preach, corresponded to 783 U. C. Now well, subtracting the 30 years of the life of Jesus he obtained that he had been born in 753 u. C. To place Jesus Christ at the beginning of a new era, 754 u. C.
had become the year 755 year 2, and so on. After each number Dionisio added the initials d. C., i.e. after Christ. To the years prior to the birth of Christ, on the other hand, a. C., labeled them i.e. before Christ. This new calendar the foundation of Rome not appeared more in year 1, but in 753 BC C. And Dionysius, who was living at that time in year 1275 of the Roman calendar (u. C.), was that he lived in the 526 new Christian era. How big will have been the excitement of the monk to become so the first man who knew in what year after Christ was! The idea of the new calendar was an extraordinary success, and immediately began to be applied in Rome. It came shortly after the Gallic (the current France) and England. It would take a little even to be accepted in Spain: in Catalonia it is adopted only from 1180; in Aragon, from 1350 Christmas; in 1358 he admits it in Valencia; in Castile since 1383.