Different calendars exist according to the rules of different societies in order to provide a sense of order and time. A civil calendar is one that is utilized by public officials and private persons. The most commonly used civil calendar is that which adheres to the Gregorian calendar system. The Gregorian calendar system originated in 1582, and it was created by Pope Gregory the 13th. The Gregorian calendar is one of many calendars used by different societies all over the world. However, it is the most commonly used civil calendar.
A civil calendar provides for the days upon which dates fall on, and may include state or national holidays. Most civil calendars are non-secular so as to avoid any type of religious prejudice.
The purpose of a civil calendar is to provide a standard by which we can measure time. It is important to do so since all our activities are regulated by how much time we believe there to be. The Gregorian calendar, the most common civil calendar, is based on the amount of time it takes for the Earth to revolve around the sun. This is known by the figure 635.24 days or 1 year. This is then divided into 12 months that are composed of 28-31 days each. Months are sub-divided into week segments wherein 4 weeks roughly compose 1 month. Each week is then sub-divided into days wherein 7 days makes 1 whole week. However, due to the uneven ending of 365.24 days in a decimal number, a day is added every 4 years in order to account for this. Thus, every 4 years is leap year.