The History of the Calendar

Joe Lanman, via Flickr

Liz Waid and Joshua Leo tell the history of the most popular way people organize time - the Gregorian calendar.

Watch Video


Voice 1 

Welcome to Spotlight! I’m Liz Waid.

Voice 2 

And I’m Joshua Leo. Spotlight uses a special English method of broadcasting. It is easier for people to understand, no matter where in the world they live.

Voice 1 

The year was 1752. On Wednesday, September 2, the people of Britain went to sleep.

When they woke up in the morning the date was Thursday, September 14. That sounds like a mistake. The date should have been Thursday, September 3, not Thursday, September 14! But this story is true. The people of Britain went to sleep on September 2. When they woke up, the date was September 14!

This strange date change was the result of a British Act of Parliament. This act was called the “British Calendar Act of 1751”.

Voice 2 

Why did the British Parliament do this? In 1752 the official calendar of Britain was behind the official calendar of Europe by 11 days. So, in the United Kingdom, the date was September 2. But in Europe, it was September 13.

Voice 1 

A calendar is very important for measuring days and months, keeping religious holidays, and observing the seasons. Britain had been following an old version of the calendar. In 1752 they finally began to use the calendar accepted by the rest of the world. This helped them trade with other countries and celebrate religious holidays at the same time as the rest of Europe.

Voice 2 

Calendars are very complex. They depend on careful measuring. And they affect many parts of the world. Today’s Spotlight is on the history of the most used calendar in the world: the Gregorian calendar.

Voice 1 

Calendars are very important to people all around the world. Calendars help us remember religious events. They help to set times for farming and hunting. They help mark events from history. They mark events happening in the sky. They mark the passing of time from century to century.

Voice 2 

Some experts believe that the ancient Roman and Egyptian people were some of the first to use calendars. They created calendars almost 3,000 years ago. The Romans based their calendar on phases of the moon - that is, how the moon appeared. The moon goes through a cycle every 29 and 1/2 days. It begins as a full moon. It slowly gets smaller and smaller. Then it begins to get larger and larger until it is again a full moon. For the Romans, a full moon was the beginning of a new month.

Voice 1 

But the Egyptians based their calendar on the sun. The sun follows a set path in the sky as the earth travels around it. There are no clear months. Instead, measuring time depends on the seasons, and where the sun is located in the sky. A year counted using this method is called a solar year.

Voice 2 

Since the Roman kingdom was so large, the Roman calendar was the most popular. But until about 46 B.C., or about 2,000 years ago, the calendar was not well organized! At first, there were only ten months on the calendar. Each month was named after a number. The year always began in March and ended in December. The Romans did not even count the months that we now call January and February. They were not considered a part of the year. But, after time, one of the emperors did divide this uncounted time. He named it and began to count it on the calendar. So then, the months named after numbers were not correct anymore!

Voice 1 

Calendar officials did not always follow the calendar rules carefully. Officials of the Roman government sometimes changed dates and lengths of months to stay in office longer! After some time, the official Roman calendar was in trouble. It did not even follow the seasons.

Voice 2 

Then the Roman emperor Julius Caesar took control. He designed an improved calendar. He changed and improved the calendar in three main ways.

Voice 1 

First, Julius based his calendar on the solar year like the Egyptians. This was important because it established the official Roman year as 365 days.

Voice 2 

Second, Julius changed the date of the official beginning of the year from March to January 1.

Voice 1 

Third, Julius changed the lengths of the months to how we know them today.

Voice 2 

Most countries of the time began using this new calendar. It was called the Julian calendar.

Voice 1 

There was one other very important change in the Julian calendar. A solar year is 365 and 1/4 days. Julius had to think of a way to count this part, or 1/4 of a day.

Voice 2 

Julius added an extra day into the calendar year. He declared the extra day should be added only once every four years. This is something that we still do today.  A year with an extra day is called a “leap year”. Today we add this extra day to the end of the month of February.

Voice 1 

The Julian calendar was a big improvement on earlier calendars. But calendars are very difficult to design. And the Julian calendar still had a few mistakes. The length of the Julian calendar year was 11 and 1/2 minutes short. This sounds like only a small counting mistake. But after many years, this small counting mistake began to add up!

Voice 2 

Every 400 years these 11 and 1/2 minutes add up to just over three days. Around the year 1582, this began to cause a problem.

Voice 1 

In 1582 the official calendar was not correctly lined up with the seasons. It was about ten days behind. Religious holidays like Easter did not happen during the right season. The Catholic religious leader, Pope Gregory the 13th, decided to fix the mistake in the Julian calendar.

Voice 2 

Pope Gregory kept many parts of the Julian calendar. But he established new, more complex rules for the leap year. His new calendar was called the Gregorian calendar. It took a long time for people all over the world to accept the Gregorian calendar. But now it is the most common in almost every country. Some cultural and religious groups do use other calendars for special cultural or religious holidays.  But for official records, most countries use the Gregorian calendar.

Voice 1 

But even this calendar is not perfect. The Gregorian calendar is 26 seconds short of a solar year. This means that every 3,300 years the official calendar will be different from the solar calendar by one day. When this happens, the world will have to fix the calendar again!

Voice 2 

The writer and producer of this program was Liz Waid. The voices you heard were from United States and United Kingdom. You can find our programs on the internet at This program is called “The History of the Calendar”.

Voice 1 

You can also leave your comments on our website. And you can find us on Facebook - just search for Spotlight radio. We hope you can join us again for the next Spotlight program. Goodbye.

(Get our app for Android or for Apple devices. Let us know how you like it and write a review!)


Do you use a paper calendar, or a calendar on your phone?


Luis Piedra's avatar
Luis Piedra
said on November 28, 2012

excellent program.
Thanks Spotlight.

Avatar Spotlight
said on January 07, 2014

Hi Liz,
I am back again. I heard your radio program today at radio 7, meanwhile I was driving, and I liked it. Since I couldn’t completely understood, I just read it again. Radio 7 is my old love. It helped me on my way of learning English. ThNk you all.

Avatar Spotlight
said on January 09, 2014

Pershendetje Skender,

Te pershendesim nga Radio 7. Faleminderit qe na ndjek. Na vjen mire qe te kemi ndihmuar me mesimin e Anglishtes. Nuk e di nese jeton ne Tirane ose ne ndonje qytet tjeter, por shume shpejt, brenda muajit Shkurt do hapen disa Klube te Anglishtes te cilat zhvillohen pikerishte nga programet e Spotlight. Nese do jesh i interesuar mund te na kontaktosh ne faqen tone te FB “Spotlight English Clubs Albania”.

Pac nje dite te bukur!

Avatar Spotlight
said on February 02, 2014

I would be able to listen your every programme on radio lively. but ı‘m in turkey and can’t listen it. But ı try to listen them on this website :)

Robin Basselin's avatar
Robin Basselin
said on February 02, 2014


Thank you for your wonderful comments! We are glad you enjoy Spotlight. If you live in either Istanbul or Ankara, you can listen to us on the following radio stations:

Radio Light, Istanbul - 103.6 FM
Every day: 00:45 to 01:00

Radio Shema, Ankara - 98.0 FM
Every day at 20:00:00 and 23:00:00

Robin Basselin (for the Spotlight Team)

Avatar Spotlight
said on August 10, 2016

This subject is interesting to find about the calendar which we use it everyday.
Thanks Spotlight a lot.

Kaleb Kolaibi's avatar
Kaleb Kolaibi
said on August 10, 2016

Some Islamic radicals are fighting against using the Gregorian calendar in Islamic countries while Saudi Arabia government ban use it even in officials offices.
I use a calendar on my phone from 2004 when I owned a mobile as a first time in my life. Before that I was used a paper calendar.
Robin Basselin; How I can listen to your radio from Ethiopia? With noted that I listening to Ethiopian local radio by English.
God bless you

Severino Ramos da Silva's avatar
Severino Ramos da Silva
said on August 10, 2016

From: .(JavaScript must be enabled to view this email address) (Severino Ramos)
To: spotlight programme
Subject: answer to the question above
Date: Wednesday 10, August 2016
São Paulo SP Brazil

Dear Liz Waid and Joshua Leo:

At first, I want to thank you to bring us readers and learners of English more one great article. Thanks!
Yes, I do. Also, I use a calendar on my phone to manage my schedule.

Yours regards,
Severino Ramos

Avatar Spotlight
said on August 11, 2016

We know the earth turns and travels around the sun. We have year, month, day and hour. We live and work. We have celebrations . We have year, month, day and hour. We live our lives for beautiful good things. We do beautiful good things and keep away from not good things. We respect beautiful good things. Time passes. We always make much effort to live a beautiful good life. We have beautiful good things. Beautiful good things exist.

Avatar Spotlight
said on August 27, 2016

You are the best speakers for me . I am happy to listen to your stories . Thank you for your hard work !

KatyBlake's avatar
said on October 13, 2016

Kaleb Kolaibi, I have asked my colleagues about listening to Spotlight on the radio in Ethiopia. This is why it has taken me so long to reply to you.

I am sorry to tell you that no radio stations in Ethiopia carry the Spotlight programme at present.

A satellite radio station called Radio Al Mahabba does have some coverage in Ethiopia, although a fairly large satellite dish is needed. This station has carried Spotlight in the past, although I’m not certain that it does at present. 

Katy Blake (for Spotlight English)

Avatar Spotlight
said on March 31, 2017

English Radio ( is excited to be partnering with Spotlight English.  We will be broadcasting this recording on Tuesday, April 4th, followed by an hour of music about money.  :)  Can anyone guess which songs we will play?

Avatar Spotlight
said on May 07, 2018

I use the calendar of my smartphone and of my computer. Thanks Spotlight for this cherful story of calendar, but a question remains: why the British calendar was different from the calendar in Europe?