Every moment in this world’s history can be uniquely identified using the system of calendar and clock. Every moment of your life has a unique time tag attached to it – the day on which it happened, the time at which it happened. The whole concept of time-identification – that is based on calendar and clock allows us to uniquely identify and refer to each moment in past, present and future.

A calendar has infinite years, with 12 months in each year, with a total of 365 days, distributed over 12 months with approximately 30 days in each month. Each day is divided in 24 hours and each hour has exactly 60 minutes, that has 60 seconds.

Have you ever wondered – why 12 months in a year and not 10? Why there are only 30-31 days in a month, not 20 or 50? If you haven’t thought about this before, perhaps it’s about time you look deeper into these things and understand how the world is working – it’s important to know about the world you are living in. And if you have given it a little thought and concluded that it’s just because that’s how people have liked it – then you gotta understand that there are solid reasons for each of these numbers – a lot of thought, calculations, reasoning behind the whole foundation of this system of time – the system that has allows and enabled us to evolve and be in sync. The entire concept of “Synchronization” as per which two people can “coordinate” has been allowed only by the concept of time.

Let’s understand what this system is based on. Unless there’s some disagreement, we can all agree on the fact that the earth is round – and revolves around a star that we call “Sun”.

Now, as scientists, philosophers and astrologers claims, our mother planet completes one revolution around the sun in exactly 365 days. Which means in reference to Sun, the earth will be back to exact point where it is today in another 365 days. The path of earth’s revolution around the sun isn’t perfect circle – but rather oval. In some parts of it’s path, the earth is farther away from sun and in some parts, it’s closer. That leads to the whole system of weather. The summers are when earth is closer – with mid of June being the time when earth is closest to Sun. And winters are when earth is farther away from the sun – leading to the cold temperatures. Have you ever thought about what would happen if Earth just slips a little farther away from Sun than usual? We’d all die of cold. Thank “God” there’s no human/government employee driving our planet’s motion.

If we get to the bottom of things, the system of time that we follow is Roman Calendar. During late 1st century BC, Julius Caesar and emperor Augustus reformed the existing system of time and gave structure to a better, more logical system that evolved to what we know today. Interestingly, there used to be only 10 months in original calendar, with the year starting from March. The winter period was later divided into two months, January and February which were added to the original calendar in order to sync it to “actual” revolution time of earth around the sun.

If interested, you can read more about the evolution of Roman Calendar here.

Although our species hasn’t seen the cycles before it’s birth – we had to take a point of reference to build the calendar. We called the day – 1st January – and the previous day 31st December BC. Hence 1 AD became the first cycle of earth around the sun that we started tracking the dates from, while 1 BC became the previous cycle from which we started the calendar. Hence 100 cycles before we started the calendar would be called as 100 BC while 1000 years after the invention of calendar is known as 1000 AD. By the same logic, 2020 is the 2020th cycle of earth around the sun after the invention of our calendar.

Now, our system of astrology is based on movement of exactly three galactic bodies in reference to each other – the Earth, the Sun and the moon. As you’d be aware – earth rotates on it’s axis. Hence we have concept of day and night. At any particular time, the part of our planet that is facing towards the Sun has day on it, while the part that is on the opposite side has night. One complete rotation of earth in reference of the sun takes exactly 24 hours. In those 24 hours – we have 12 hours in which our side of the planet is facing towards the sun and 12 hours on which it’s facing away from the sun – hence we have a day of 12 hours (7am to 7pm mostly – subject to which year it is and the distance of sun and the planet).

Ideally, we didn’t have to invent the concept of months. The system of 365 days in 1 year was sufficient to refer to earth’s position around the Sun – but we have another galactic body that’s important – moon. You couldn’t possible be thinking the moon actually reduces it’s weight when we see half moon or other shapes of it…

Turns out, Our Moon keeps on revolving around our planet – and is significant to our weather, tides and various other phenomenons. The hidden or dark part of the moon is actually because of the Earth’s shadow on the moon – which means when earth’s shadow is completely over the moon – that’s eclipse. While the opposite of it leads to the full moon – when earth’s shadow is completely away from the moon. That is based on the position of the sun, the earth and the moon in respect to each other.

Scientifically, moon takes exactly 27.3 days to complete one revolution of earth. While not accurate, but it comes down around a month.

By the way, have you ever wondered the existence of Hindu Calendar? We Hindus were late towards adopting the Roman calendar, and hence we’ve been using a calendar of our own in parallel. That is why most of our religious days keeps changing every year – including Diwali which could be anytime in late October or early November. That is because the Hindu calendar follows a different belief system that’s based on the movement of Moon and Sun (hence called as Lunisolar). If you’d like to know more about Hindu Calendar – read here.

Coming back to the concept of months – 1 month is approximate time it takes for moon to complete a cycle of earth. But why are there 4 weeks in a month?

As so it happens, The Babylonians are to blame for the concept of weeks. They originally were astute observers and interpreters of “heavens” or say “Sky”/Space. They observed 7 celestial bodies – namely the Sun (leading to Sunday), the Moon (leading to Monday), the Mercury, the Venus, the Mars, the Jupiter and the Saturn (Saturday) – Excuse my ignorance to not dig deeper and coorelate these celestial bodies with their days.

Apparently, The Babylonians’ calendar had 4 weeks in a month and each month hence had 28 days – which was more accurate than our system of identifying months. However, we chose the Romans over Babylonians so let’s get over it.

The same babylonians are to blame for there being 60 minutes in an hour and 60 seconds in minute. The division of the hour into 60 minutes and of the minute into 60 seconds comes from the Babylonians who used a sexagesimal (counting in 60s) system for mathematics and astronomy. They derived their number system from the Sumerians who were using it as early as 3500 BC. The use of 12 subdivisions for day and night, with 60 for hours and minutes, turns out to be much more useful than (say) 10 and 100 if you want to avoid having to use complicated notations for parts of a day. Twelve is divisible by two, three, four, six and 12 itself – whereas 10 has only three divisors – whole numbers that divide it a whole number of times. Sixty has 12 divisors and because 60 = 5 x 12 it combines the advantages of both 10 and 12. In fact both 12 and 60 share the property that they have more divisors than any number smaller than themselves. This doesn’t, of course, explain how this system spread throughout the world.

That’s all for now folks. Hope this helps you make more sense of this fucked-up super-complicated world. Peace out!