Encoded Trivia #24

About This Answer

April, June, September, and November each have 30 days, following the irregularities of the Gregorian calendar established in 1582. According to calendar historians at the Vatican Library, this system was created by Pope Gregory XIII to correct the Julian calendar's drift from the solar year. The British Museum documents how calendar reform affected commerce, agriculture, and religious observances throughout Europe. Modern astronomers use this calendar for celestial event predictions and space mission planning. The 30-day months represent a compromise between lunar and solar timekeeping systems that has served humanity for over four centuries.