: All you need to know about evolution of calendars and time #IndiaNEWS #Education Hyderabad: Ancient civilizations, like the Babylonians, Egyptians, and Romans, had a large role to play in the way

All you need to know about evolution of calendars and time #IndiaNEWS #Education
Hyderabad: Ancient civilizations, like the Babylonians, Egyptians, and Romans, had a large role to play in the way we tell time and in the modern calendar, we use today.
Read here how time appropriation evolved over the centuries….
How did we come to divide the hour into 60 minutes and the minute into 60 seconds? These smaller divisions of time have been in practical use for only about 400 years, but they were vital to the advent of modern science.
For millennia, ancient civilizations looked to the sky to measure the big units of time. Theres the year, which is the time it takes Earth to complete one orbit around the sun; the month, which is approximately how long it takes the moon to orbit our planet; the week, which is approximately the time between the four phases of the moon; and the day, which is the duration of one rotation of the Earths on its axis.
Dividing the day was not so straightforward, though hours and minutes have their origins in traditions tracing back thousands of years
Number systems
The use of 60 began with the Sumerians who used different number systems. While you and I write numbers using base 10, or “decimal�? this civilization used base 12 (duodecimal) and base 60 (sexigesimal). It is not known exactly why they chose these systems, but there are a few theories
• Many ancient cultures used the three segments of each finger to count to 12 on one hand. It is hypothesized 60 arose from using five fingers of one hand with the twelve segments of the other.
• Fewer fractions have repeating decimals (1/3 = 0. 333…) when written in sexagesimal. This is particularly important because the Sumerians had no notion of repeating-digit fractions.
• Twelve was an important number to the Sumerians, and later to the Egyptians. For example, it was the number of lunar cycles in a year and the number of constellations of the Zodiac. Day and night were each divided into 12 periods, and the 24-hour day was born.
Sumerian legacy

Today, 5,000 years after the Sumerians first began using 60, we divide our days by hours, minutes and seconds.
Timeline of calendars
3100 BC
The Sumerians were the first to use calendars in Mesopotamia during the Bronze Age. Each month on this calendar had 29 or 30 days, depending on whether or not the first day had a full moon.
2510 BC
The Egyptians created their calendar. The Egyptian calendar had 12 months but they had 5 extra days in their year.
738BC
The first Roman calendar was introduced by King Romulus. This calendar had only 10 months, starting in March and ending in December.
400BC
The Greeks had many lunisolar calendars they used to keep track of time. The Athenian calendar, also known as the attic or civil calendar, was the most common, but the Greeks also created the Olympiad, Seasonal, Conciliar, and Metonic calendars.