Gregorian calendar

The **Gregorian calendar** is the internationally recognized civil calendar used by most countries around the world today. Introduced by Pope Gregory XIII in 1582, it refined the earlier Julian calendar to better align the calendar year with the solar year, correcting drift caused by leap year calculations. The system organizes the year into 12 months, incorporates leap years every four years with exceptions for century years, and standardizes dates for civil, religious, and cultural purposes. This calendar plays a central role in global timekeeping, holidays, and historical record-keeping.