<Li> From 25 December 753 AUC (today in 1 BC), i.e., notionally from the birth of Jesus . It was called "Nativity style" and had been spread by the Venerable Bede together with the Anno Domini in the early Middle Ages . That reckoning of the Year of Grace from Christmas was used in France, England and most of western Europe (except Spain) until the 12th century (when it was replaced by Annunciation style), and in Germany until the second quarter of the 13th century . </Li> <Li> From 25 March 754 AUC (today in AD 1). That second "Annunciation style" may have originated in Fleury Abbey in the early 11th century, but it was spread by the Cistercians . Florence adopted that style in opposition to that of Pisa, so it got the name of calculus florentinus . It soon spread in France and also in England where it became common in the late 12th century and lasted until 1752 . </Li> <Li> From Easter, starting in 754 AUC (AD 1). That mos gallicanus (French custom) bound to a moveable feast was introduced in France by king Philip Augustus (r . 1180--1223), maybe to establish a new style in the provinces reconquered from England . However, it never spread beyond the ruling élite . </Li> <P> With these various styles, the same day could, in some cases, be dated in 1099, 1100 or 1101 . </P>

Does a d and c count as a period