Hailey Heseltine
ECB Publishing, Inc.
Sixty seconds, sixty minutes, twenty-four hours, three hundred sixty-five days, fifty-two weeks, twelve months—we all recognize this as ways we keep time, how we identify our present in comparison to the past and future. But did you know that the way we perceive time has not always been the same? Historically, there have been many different ways ancient cultures kept time before most decided to settle on the solar-based timekeeping system we use today. In fact, the Roman calendar even used to have only ten months. So, when were these changes made, and why?
The Roman calendar, supposedly instituted about 738 BC, was likely derived from the Greek lunar calendar. As a result, it had only ten months—around 304 days—per year. That left a little over 61 days in the lurch during winter. Two months were later added by Numa Pompilius, a Roman ruler, in the 700s B.C.E. to equal the twelve months we know today. He added January at the start of the year and February at the end. Later, February was moved to be between January and March instead. The calendar system became a complicated combination of the solar and lunar cycles, and neither harmonized effectively. The result was 355 days per year with the occasional extra month called mercedonius in the hopes of catching up with the solar time. Since rulers had the authority to toy with the calendar as they pleased, it often changed to suit whatever political outcome they desired, whether it was to lengthen or shorten a term. The calendar finally became more consistent when Julius Caesar decided it needed a reform in 46 B.C.E and developed the Julian Calendar, which gave some months 31 days, others 29, and February 28. The mercedonius was once every two years and around 23 or 24 days, making the average year around 366 days over the span of four years. Despite its imperfections, it formed a fantastic basis for future calendars.
However, the inconsistencies of the Julian Calendar eventually showed—time slipped back one day every 130 years. Discontent arose because the date of Easter began deviating drastically from the Jewish Calendar; if the equinox was incorrect, then so was the date they celebrated Christ's resurrection and all corresponding holidays. Thus, a reform was made in the fifteenth century when Pope Gregory XIII, with the aid of mathematician and astronomer Christoph Clavius, instituted the new calendar. Though there were many changes, the most relevant change was that of leap years—one leap day is omitted per 400 years and the leap year is every four years. The result is the Gregorian calendar we use today—an effective change of pace for us all.