To make up for the lost 10 days from the Julian Calendar, the Gregorian Calendar simply moved up the date to skip 10 days. Once they knew why the calendar date and the season of the year were off, it was time to get back on track. The new calendar recalculated the leap years to make the average length of a year more accurate. In 1582 AD, this new, “Gregorian Calendar” was introduced, named after Pope Gregory XIII, who pushed for the change. So, they created one that would be more accurate over time. It became pretty obvious that a new calendar was needed. That 11 minutes added up year after year, and by the 1570s, Pope Gregory XIII and his peers realized that their calendar was off by 10 days! With help from astronomers and mathematicians, they figured out that the Julian Calendar was miscalculating the length of the solar year by 11 minutes. The first page of an edict from Pope Gregory XIII, in which he introduced his calendar.įor example, it’s been suggested that the original goal of the Gregorian Calendar was to correct the date for Easter, which seemed to be getting further and further away from the spring equinox.
