In the context of the calendar, Vol. 3-1964 of the children'sBritannica gives a brief description of its history. Calendar means a way of dividing time on the basis of year, month, days, the movement of the earth and the moon. Luna is the Latin word for the moon. Hence, it is known as the Lunar month. The Latin word for sun is Sol; therefore we call it a solar year.
Today, it measures 365 days, 5 hours, 48 minutes and 46 seconds. Since there is no co-ordination between the solar years and the lunar month, there was confusion or disorder in many countries. Another reason for this confusion was the lack of knowledge.
Secondly, comes the point of dividing time on the basis of a historical event, Christians believe that the birth of Christ is the deciding event of history. On the basis, they divided history into two parts-(1) BC, which means the period before the birth of Christ and refers to incidents that took place before the birth of Christ, and (2) The events that occurred after the birth of Christ are called AD which stands for Anno Domini which means in the year of our Lord. It is a different matter that this method was not in use for some centuries after the birth of Christ.
Today'sAD year is based on the Roman calendar. It started with the establishment of the city of Rome?753 years before the birth of Christ. Initially it had a 10-month year which lasted from March till December and had 304 days. Later on, King Pimpolius added two months, Jonu Arius and Februarius to it and made it 12 months with 355 days, but in later years, because of the movement of the planets, the difference kept on increasing. Then, in 46 BC, Julius Caesar ordered a new calendar which had 365? days so as to set the difference right. That is why, in history, year 46 BC is known as the ?Year of Confusion?.
Caesar gave 365? days to a year. Serially, the months were given 31 and 30 days. February had 29 days, but in a leap year, it had 30 days. Along with this, to immortalise his name, he changed the name of the seventh month from its old name Quinitiles to July, which had, and still has 31 days. Later on came Emperor Augustus, who changed the name of the eighth month from Sextilis to August, to immortalise his name. At that time, August had 30 days but, to show that he was as great as Caesar, he took one day off from February, which contained 29 days then, and added it to August. Since then, the days and the months have continued to remain the same.
In the 16th century, the Julian calendar was increased by 10 days and the church festivals like Easter etc started getting into trouble. So, Pope Gregory XIII issued an order in 1582 to rectify it by observing 4th October as 15th October and the beginning of the year from January 1 instead of March 25. The Roman Catholics accepted the order of the Pope with immediate effect but the Protestants took some time to accept it. Britain kept following the Julian Calendar and by 1752, there was a difference of 11 days. Hence, to rectify it, the day after September 2 was observed as 14th September. At that time, people used to shout slogans of ?Criseus back our 11 days.? After England, Bulgaria accepted the Gregorian Calendar in 1918 and then, in 1924, the Greek Orthodox Church also adopted it.
History of Measurement of Time in India
India had the tradition of studying minute planetary movements. Calculations continued to be made on the basis of the movements of the earth, moon and the sun. To bridge the difference in the motion of the sun and the moon, there has been a practice of adding an extra month (Adhik maas). The various units of time and their reasons have been described below in brief:
Day?Saawan day-The earth rotates on its axis at a speed of 1600 km per hour. To complete one rotation, it takes 24 hours. That part of the earth which stays in front of the sun for 12 hours has been called Ahah and the part that is behind, has been called Raatr. This way, there are 24 horas in one ahoraatra. It seems as if the word ?hour? in the English language is the slang form of the hora. Saawan din has been called Bhoo din (Earth Day).
Saur day?The earth is going around the sun at a speed of 1 lakh km per hour. A one degree movement of the earth is called a Saur din (Solar Day).
Chandra Din or tithi?A Chandra din or lunar day has been called a tithi, for example Ekam, Chaturthi, Ekadashi, Purnima, Amavasya, etc. The movement of the moon to the twelfth part, while going around the earth, is called a tithi?
Saptaah (Week) ?The days of the week and their sequence throughout the world are the same as has been discovered in India. The sequence of the planets was determined as per their progressive distances from the earth. Hence, Saturn, Jupiter, Mars, Sun, Venus, Mercury and Moon. Of these, the moon is the closest to the earth and Saturn is the farthest. Each planet is the ruler for one hour out of the 24 hours or hora day. Hence, each of the seven plants become the ruler for one hour by turn. This cycle goes on and once the 24 hours are complete, the name of the next day is according to the planet that is the ruler in the first hour of that day. Since creation started with the sun, hence the first day of the week was Sunday and the other days were named sequentially.
We can easily understand the sequence of the seven days as per the table given below: