A calendar is a system of organizing days for social, non secular, industrial, or administrative functions. The phrase “calendar” comes from the Latin phrase “calends,” which referred to the primary day of the month within the Roman calendar. Calendars are used to maintain observe of appointments, occasions, and holidays. Companies use calendars to schedule conferences, observe deadlines, and plan tasks. Colleges use calendars to plan the educational 12 months and schedule lessons and exams. Households use calendars to maintain observe of appointments, actions, and holidays.
The Gregorian calendar is essentially the most broadly used calendar on the planet immediately. It was launched in 1582 by Pope Gregory XIII and relies on the photo voltaic 12 months, which is the time it takes for the Earth to orbit the solar. The Gregorian calendar has 12 months, with 28 days in February in a standard 12 months and 29 days in February in a intercalary year. Leap years happen each 4 years, aside from years which are divisible by 100 however not by 400.