Gregorian Calendar
The Gregorian calendar is a solar calendar system introduced by Pope Gregory XIII in 1582 as a reform of the Julian calendar. It is the most widely used civil calendar in the world today, designed to align the calendar year with the solar year to maintain seasonal accuracy. It operates on a 365-day common year with leap years added according to specific rules to account for the Earth's orbit around the Sun.
Developers should learn about Gregorian calendar rules when working with date and time handling in software, such as in applications involving scheduling, historical data, or internationalization. Understanding these rules is essential for accurate date calculations, leap year detection, and avoiding common pitfalls in date-related logic, especially in systems that require precise timekeeping across different regions.