It’s 21st November 2018 today. Did you ever think how do we know it’s the 21st today? Or how do we know it’s a Wednesday? Let us all just take a minute to thank Pope Gregory XIII, the man who introduced the modern calendar to us. Without his discovery, I don’t think we would’ve ever known or even remembered our own birthdays or anniversaries!
As we all know, the phenomenon of days, months, years, its all based upon the course of the sun and the moon. It is regarded as one of the most reliable regularly occurring events for measuring time. The ancient history of calendars tells us that timekeeping was done on the basis of lunation and ‘year’ was considered as a time unit. The pre-modern history of calendars basically consisted of a solar calendar which was based on the revolution of the earth around the sun. Egyptians were the ones who followed solar calendars. Lunar calendars were based on the phases of the moon and the Sumerians used this type of calendar. Another calendar in the ancient times was a lunisolar calendar, which acknowledged both, the phases of the moon and the solar year. The biblical calendar would be an example of a lunisolar calendar.
Humanity since long has been measuring the progression of time using the different celestial/heavenly bodies to keep an eye on the movement of earth and changes in seasons. However, determining the calendar order of the past is not always reliable, as the documentation of the data was poorly done due to lack of proper knowledge or inadequate technology or apparatus. If we talk about the Stonehenge in England, it is a prehistoric monument which consists of a ring of standing stones, the purpose of Stonehenge is still unknown but the archaeologists believe that the massive rocks might have indicated some kind of calendar, representation of the solar system.
During the last millennium of BCE, the Roman calendar was regarded as the Old World Standard, but it could not last long due to its strange form. It only consisted of 10 months that were either 30 or 31 days long, which began in March 2019 Calendar Printable and ended in December. At first, the winter season wasn’t accounted for, but the eventual addition of January and February extended the total year to closely match the existing solar year. Despite this change, the Roman calendar was incredibly complex and required to remove or add days very often to keep the calendar in accordance with the seasons. This led to Emperor Julius Caesar’s purpose for an update in 45 BCE which was done along with Alexandrian astronomer Sosigenes, thus the Julian Calendar was formed. There were various key changes introduced in this calendar which included the concept of a 365-day year and the addition of leap year once in every 4 years. Following this time, the Julian Calendar became the standard calendar as it spread usage across the whole Roman Empire, but there wasn’t really a form of the era. Different people conceived the majority of this as a way to conclude the time in which the earth came into existence based on their respective cosmologies. Introduction of Anno Domini led to the fall of the Roman Calendar. The AD was accepted all over Europe but there was a major issue with the standard Julian Calendar: it miscalculated the length of the solar year by 11 minutes, which was enough to make a difference in the seasons. This motivated Prop Gregory XIII to alter the dysfunction in the calendar. The concept behind the Gregorian calendar is based upon leap year. Gregory along with an Italian scientist Lilius realized that the addition of leap day every 4 years made the calendar slightly long so they revised the idea of leap year and gave us the Gregorian calendar which we use today.