Days, Weeks, Months and Years

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Introduction to Days, Weeks, Months and Years


The theory of day and night goes back to our Simian predecessor. You might be surprised to know that the Indo-European week was of 9 days (a 3rd of a month). This is why in so many languages the term for “nine” and “new” is so plainly related. The days of the week were named by the Babylonians (ancient Akkadian-speaking state in central-southern Mesopotamia) after the Sun, the Moon and the five known planets. Germanic nations named the days in their 7 day week.

Days of The Week

  • Monday

  • Tuesday

  • Wednesday

  • Thursday

  • Friday

  • Saturday

  • Sunday

Saturday and Sunday are considered as the weekend and thus fall at the termination of the week.


A week is basically a breakdown of a monthly cycle of 29.5 days into 4 intervals of 7 days each; using leap days to remain in sync with the moon phases in the long-run. It is an easy way to constitute all phases of the moon as it completes a full orbit everywhere about the earth. It takes a period of about 15 days from new moon to the full moon, as seen from earth. A month (4 weeks) is equal to about 2 cycles of the new moon to new moon.


A month is a breakdown of the year into 12 cycles = about 29.5 days = around the interval for the moon to complete a full orbit of the earth (the actual cycle is of approximately 27.3 days, which is why we have leap days to consider for the variance).

If you have observed months do not fit clearly into years. This is to say each month does not hold equal days. The Babylonians had an opinion that 360 accounts for a number of prime factors that it was a number apt for a heavenly body, but a 7 day week did not fit clearly into this. Julius Caesar’s calendar reform in 46 BC got around this by months which substituted between 30 and 31 days. His nephew Augustus did not like having a birth month of only 30 particularly as his uncle’s July had 31 days so he disturbed things by doing out February of a day to make up for the difference.

As already mentioned, a year is divided into 12 months. A month either has 30 days or 31 days (except February having 28 days and 29 in a leap year). Following is the cycle of months:

Months of The Year


Number of Days




28 or 29






















The year is an approximate breakdown into 365 days = the interval for the earth to fully achieve a full orbit of the sun.

Seasons of The Year

  • Summer

  • Winter

  • Spring

  • Autumn/fall

Fall is the term used in the United States, whereas autumn is used elsewhere in the world.

Solved Examples


Calculate the number of days in a year.


for the purpose of finding  the number of days in a year we would require to calculate:

[7 × 31] + [4 × 30] + [1 × 28]

= 217 + 120 + 28

= 365

For leap year

[7 × 31] + [4 × 30] + [1 × 29]

= 217 + 120 + 29

= 366


Find out the next leap year that comes after 2000.


We are already familiar that,

1 week = 7 days.

Now in order to determine the number of weeks in a year, we are required to divide 365 by 7.

Thus, 365 ÷ 7 = 52 weeks and 1 day

We can learn from the calendar that

7 days = 1 week

Approximately 52 weeks = 1 year

12 months = 1 year

365 days = 1 year

366 days = 1 leap year

Approximately 4 weeks = 1 month

10 years create one decade.

100 years create one century.

1000 years create one millennium.

Fun Facts

  • The days of the week, months of the year in English always begin with CAPITAL letters. For example:

February correct - february incorrect.

Wednesday correct - wednesday incorrect.

  • The first letter of the seasons does not start with capital letters.

FAQ (Frequently Asked Questions)

Q1. When does Days, Month, Week, Year come into Existence?

Answer: The division of time period in terms of month, year, week or days has been in existence since ancient times. The theory of the 7-days week originated from the Babylonian; while the division of the year, month and days have been in existence in various ancient civilizations since times off forebears.

The Babylonians divided their month by 4 and obtained 7, a concept they also imparted to the Jews during their times of captivity and the Christian Church went along with the concept. And amazingly, for a reason unknown the Romans adopted the Jewish week even before they had converted to Christianity.

Q2. How do Days get its Name?

Answer: Days were basically named in Latin after the names of gods. The Germanic nations assigned the days in their 7 day week after the names of their gods in correspondence to the Latin planetary gods. For example, Thursday, given as the day of the planet Jupiter, is named after the God of Thunder- Thor, regarded as the Germanic god of thunder and is named in English.

Q3. How do Months get its Name?

Answer: This has a unique telltale to it. A piece of bone from Stone Age has been discovered marking off the days of the month, apparently by a Paleolithic woman working out the day of her next month ovulation cycle. This itself makes us know how far back months were known of and even that people deemed in years several thousand years BC.