Calendars Around the World

Have you ever wondered why Chinese New Year falls on a different date each year? Or why Christmas is always on the same date but Easter changes? Ramadan is on a different date every year, too. Well, it depends on which calendar you're using.

The calendar now in general use worldwide, for secular purposes at least, is called the Gregorian Calendar (we'll discuss the exceptions of Iran, Afghanistan, Nepal and Ethiopia further down). It is a solar dating system proclaimed by Pope Gregory XIII in 1582. It was based on the Julian calendar established by Julius Caesar, on the advice of Alexandrian astronomer Sosigenes, who introduced the Egyptian solar calendar.

This system divided the year into 12 months which all had 30 or 31 days except for February, which had 28 days, and 29 days in every fourth year. The Julian measurement calculated the solar year as 365.25 days, however it is actually 365 days, 5 hours, 48 minutes, 45.25 seconds.

By Pope Gregory's time, the date did not match the season, so he advanced the date by 10 days. Also, in the Gregorian calendar, century years cannot be leap years unless they are exactly divisible by 400 (such as 1600 and 2000).

The Egyptian exception

The Ancient Egyptian Calendar, unlike its contemporaries that focussed on the Moon, was based on the Sun and was the predecessor to the Julian Calendar. It had 365 days and 12 months, each consisting of three, 10-day weeks. The last five days of the year were the birthdays of five deities. There were three seasons, however the calendar got further and further away from correlating with the seasons because they did not have a leap year.

The Coptic Calendar

The Egyptian exception leads us to the Coptic Calendar. When Pope Gregory implemented the Gregorian Calendar in 1582, Christians who were not aligned with the Roman Catholic Church decided to stick with the Julian calendar (at least initially). The Coptic Orthodox Church, a Christian church founded in Egypt by the Apostle Mark, has its own calendar based on the Ancient Egyptian system.

According to the Coptic calendar, the first day of the year is 11 September, or 12 September in leap years and Christmas – the birth of Jesus – is celebrated on 7 January. Easter – when Christians believe Jesus rose from the dead – is celebrated on the same day as some Orthodox Easters (determined by the Julian calendar). In contemporary Egypt, Easter Monday is a public holiday and it also coincides with Sham El Nessim, a national festival marking the start of Spring that dates back to ancient times.

The Ethiopian Calendar

The Ethiopian Calendar, also known as the Ge'ez or Amharic Calendar, is based on the ancient Coptic Calendar.

It also has 12, 30-day months plus five or six days, sometimes known as the thirteenth month, to match the Sun's cycles. Like the Coptic Calendar, Ethiopian New Year, called Enkutatash, is celebrated on 11 or 12 September according to the Gregorian Calendar. Another big celebration for Ethiopian Orthodox Christians is Meskel, celebrated on 27 or 28 September to commemorate the Finding of the True Cross, on which Jesus was believed to be crucified.

Ge'ez is the ancient language of northern Ethiopia and southern Eritrea. Amharic, Afan Oromo, Afar, Somali and Tigrigna are the official languages of contemporary Ethiopia (the later four were added in 2020).

Nepal's nuances

Nepal is another country that does not use the Gregorian Calendar. The official calendar is called Bikram Sambat or Vikram Samvat. It's a lunar Hindu calendar used in Nepal and some Indian states.

There's also Nepal Sambat, another lunar calendar used to determine the dates of religious festivals, birthdays and death anniversaries. One of the most important festivals in Nepal is Dashain, which generally happens from late September to mid-October at the end of the monsoon season.