All of these events can have wide variations of more than a month from year to year. Some other schools, including some in the United States, have four marking periods. Some schools in the United States, notably Boston Latin School, may divide the year into five or more marking periods. Some state in defense of this that there is perhaps a positive correlation between report frequency and academic achievement. The Gregorian calendar was adopted by much of Catholic Europe in 1582, as directed by Pope Gregory XIII in the papal bull Inter gravissimas, which was published in February of that year. Protestant and Eastern Orthodox countries initially refused to abide by…