Why did pope Gregory ant to change the Julian calendar?

Pope Gregory XIII sought to reform the Julian calendar because it was misaligned with the solar year, causing discrepancies in the timing of important dates, especially Easter. The Julian calendar had a year length of 365.25 days, which resulted in a drift of about 11 minutes per year. This accumulation led to a significant shift over centuries, prompting the need for a more accurate system. In 1582, he introduced the Gregorian calendar, which adjusted the leap year rules to better align with the Earth's orbit around the Sun.