Mesoamerican calendars was of ritual significance to a number of Mesoamerican cultures. A third major calendar form known as the Long Count is found in the inscriptions of several Mesoamerican cultures, most famously those of the Maya civilization who developed it to its fullest extent during the Classic period (ca. 200–900 CE). The Long Count provided the ability to uniquely identify days over a much longer period of time, by combining a sequence of day-counts or cycles of increasing length, calculated or set from a particular date in the mythical past. Most commonly, five such higher-order cycles in a modified vigesimal (base-20)
Year of three popes popes have held office in a given calendar year. Years in which the Roman Catholic Church was led by three different popes include: There was also a year in which the Roman Catholic Church was led by four popes, called the Year of Four Popes: Year of three popes A year of three popes is a common reference to a year when the College of Cardinals of the Catholic Church are required to elect two new popes within the same calendar year. Such a year generally occurs when a newly elected pope dies or resigns very early into his papacy.