Critical Thinking Beyond Your Job - The Roman Calendar Story

If you think that Critical Thinking is only a skill that will help you in your job or professional life, then think again. 

Critical thinking is a mindset that encourages us to question the status quo and to try to find the root causes. It helps you in problem-solving, and it also aids you in day-to-day activities.

Did you ever ask yourself why our current calendar months have these names? I did, and I was always intrigued to notice that September means "seventh month," not the ninth month as we know it today. Anyone who speaks or studies one of the Romance (Roman/Latin-based) languages like French, where seven is "sept," Spanish "siete," or Italian "sette" might have questioned this as I did.

Simply put, in Latin, "Septem" means seven, "Octo" in October means eight, "Novem" in November means nine, and "Decem" in December means ten.

So, I started applying the critical thinking process to the calendar, and I was shocked by how messed up the current calendar is.

Let's take a look at the history of the calendar and the reason why the month names starting from September (the seventh month) are not accurate in their order.

Roman Calendar:

The Roman calendar was a lunar calendar with 304 days every year. Originally, the Roman calendar had ten months, with the year starting in March (Martius) and ending in December. So, January and February didn't exist in the original Roman calendar.

The first four months were mainly named after Roman gods and goddesses from March (Martius) to June (Juno). After that, they counted the months with numbers, from 5 to 10.

July and August were initially known as Quintilis (the fifth) and Sextilis (the seventh), respectively. The Romans kept trying to make the calendar system closer to the solar year, so later on, January and February were added (at the end of the year), and they were 29 days each.

Julian Calendar:

Julius Caesar was not happy with the lunar calendar and was inspired by the Egyptian solar calendar. He decided to make reforms to the Roman calendar in 45 BCE.

The Julian calendar was introduced to the Roman Empire as the new calendar system. It changed the month counts for each month and also introduced leap years, so naturally, February (the last month of the year) had an extra day in leap years.

In 44 BCE, the Roman Senate renamed Quintilis to Julius (July) in honor of Julius Caesar, who was born in that month.

Another mess in the calendar happened later when the Julian calendar changed the start of the year to January instead of March and left everything else as is, so the seventh month shifted to become the ninth, and February became the second month and not the last.

After Caesar's assassination, his adopted son and successor, Octavian (later known as Augustus), became the first Roman emperor. 

The name "Octavian" means "the eighth" in Latin, as Octavius was the eighth in his family line to bear that name. In 27 BCE, the Roman Senate conferred upon him the title of Augustus, which means "revered" or "majestic."

In 8 BCE, the Roman Senate renamed Sextilis to Augustus (August) in his honor.

The calendar mess continued as they discovered that August was 30 days, which was not proper for the Roman emperor to have fewer days in the month named after him. So, one day was taken from February (which originally had 29 days in non-leap years) and added to August, making it a 31-day month as well. This was done to ensure that both July and August had equal prestige and status, aligning with the honor bestowed upon Julius Caesar and Augustus.

However, the Julian year consisted of 365.25 days, which was inaccurate compared to the solar year. This system overestimated the length of the solar year by approximately 11 minutes and 14 seconds. So, another calendar reform was needed.

Gregorian Calendar:

Pope Gregory XIII introduced a new calendar to fix the leap year problem in 1582. This adjustment reduces the average year length to 365.2425 days, which is much closer to the actual length of the solar year, about 365.2422 days.

In the Gregorian calendar, years divisible by 100 are not leap years unless they are also divisible by 400 (e.g., 1600 and 2000).

By the year 1582, this regression in the measurements had accumulated to 14 days. However, the Gregorian calendar also made reforms backward to the dates, causing some days to have a difference of 10 days, some 13, and some 14 (according to the year).

The Gregorian calendar advanced the calendar by 10 days after October 4, 1582, with the day following declared as October 15. In other words, the day that was supposed to be on Earth's orbit around the sun as the 5th of October was adjusted to be the 15th of October.

I attached a screenshot from my iPhone to show evidence of this change; you can check your phone or online for the same.

Ready for one final issue with the calendar? Because of the above calculations, Christmas (the birth of Jesus Christ) also shifted to the 25th of December instead of the 7th of January, in other words, the day that was supposed to be in Earth's orbit around the sun. However, not all Christian churches immediately adopted the Gregorian calendar, particularly those in Eastern Europe and the Middle East. Instead, they continued to use the Julian calendar for religious purposes, with Christmas being celebrated on January 7th in churches that follow the Julian calendar. 

Today, these countries use the Gregorian calendar, but they didn't change Christmas day to the 25th of December (now you know why).

One final thought: The current calendar is still not 100% accurate; it is deviated by only 0.0003 days (about 26 seconds) every year, so every 3,300 years or so, there might be a difference of 1 day. But I'm not sure I will be able to write another article about it when it happens :)

As you can see, by utilizing critical thinking, you can gain additional knowledge, conduct thorough research, and identify root causes.