The world has just celebrated New Year on January 1, and I am sure all of you are smart enough to know that this New Year is one that people globally follow for the sake of uniformity and for general every day purpose, while many countries and cultures consider the end of a year and the beginning of a new one to be that which is related their religion or culture.

There are many different kinds of calendars being actively used around the world and are basically of three types – solar, lunar and lunisolar/solilunar calendars. As the name suggests, a solar calendar is concerned with Sun, or, more precisely, it is based on the Earth’s rotation around the Sun. Lunar calendars are based on the rotation of the Moon around Earth and are used mainly for religious purposes, while lunisolar or solilunar calendars combine the two kinds and are basically solar calendars with dates indicating the moon phase.

Let us look at the most significant and widely followed calendars around the world and their significance for the cultures and the people they belong to.

Mayan

The oldest known measurement of a calendar year was by the Mayans so we will start with this. The Mayans were experts in mathematics and primitive astronomy. It is estimated to have been established around fifth century BC and used by the Aztecs and Toltecs.

It is a system of three calendars or dating systems – the Tzolkin (divine calendar), has 260 days associated with good and bad luck; the Haab (civil calendar) having a length of 365 days, 18 months of 20 days, plus 5 extra days and 52 cycles; and the Long Count is of 20 days.

A stone tablet discovered in the 1960s, in Tabasco, is supposed to have contained predictions of the world’s end on December 21, 2012. It was basically the end of a cycle in the Mayan calendar that was turned into a Doomsday phobia much like that which everyone was obsessed with when the year 1999 was coming to an end.

Chinese

The Chinese calendar is an example of a solilunar calendar with 12-year cycles, each related to a specific animal, with 12 months in each year and an intercalary month every two to three years. It is a very old calendar with the New Year falling on February 10 in 2013, and it will be the 4711th year in the Chinese calendar.

The new Chinese year will be the Year of the Snake, and other East Asian countries use a similar calendar except for some changes related to the animals associated with each year. The Chinese New Year falls between January 21 to February 21, depending on when the new moon of the first lunar month falls. The Chinese New Year celebration is a 15-day long observance known as ‘Spring Festival’, and it is the most important of the traditional Chinese holidays.

The Chinese year is symbolised by one of 12 animals — the rat, ox, tiger, rabbit, dragon, snake, horse, sheep, monkey, rooster, dog, and the pig — and one of the five elements — wood, fire, water, metal, and earth. The five elements are rotated every two years with the addition of yin and yang.

Egyptian

The earliest Egyptian calendar was based on the moon’s cycles, they then adopted a solar calendar of 365 days and the earliest date recorded in the Egyptian calendar corresponds to 4236BC of the Gregorian calendar.

A system of 36 stars marked out the year and they then developed three different calendars that were used concurrently for over 2000 years. There was a star-based or stellar calendar for agriculture, a solar year of 365 days and a quasi-lunar calendar for festivals.

Hijrah (Islamic)

The Islamic calendar is a pure lunar calendar with 12 months, each month being either of 29 or 30 days. It is counted from the Hijrah, when Prophet Mohammad (P.B.U.H) emigrated from Mecca to Madina, which corresponds to July 16, 622AD.

A month starts with the first sighting of the lunar crescent by the human eye after a new moon and each new day begins at sunset. With each year of the Islamic calendar being shorter than the Gregorian year, the months move through the seasons and it takes approximately 33 years for the calendar make a full round of the seasons. We are now in the 1434th year of the Hijrah.

Persian/Iranian

Despite being one of the oldest calendars in the world, the Persian calendar is considered the most accurate solar calendar used today. The reason is that it is based on astronomical measurements as opposed to mathematical calculations.

A year contains 12 months of 29 to 31 days, and a new year starts at the spring equinox, which will be on March 30 this year.

Hebrew

It is a solilunar calendar that contains 12 months, plus an extra ‘intercalary’ or leap month about every three years. It is a very old calendar where the Jewish New Year in 2013 would bring year 5773. Rosh Hashanah, or the Jewish New Year, is celebrated in autumn on the first two days of the seventh month of the Hebrew calendar.

Indian/Hindu

Last reformed in 1957, this lunisolar calendar start on Baisakhi, which marks the start of the harvest season, falling on April 13 in 2013. There are 12 lunar months and each month begins with the new moon before sunrise. There are 29 to 30 days in a lunar month as against 30 to 31 days of a solar calendar and leap years coincide with those of the Gregorian calendar. The months have traditional Indian names.

The Hindu religion divides time in four eras called ‘yugas’ (ages): Satya Yug, Treta Yug, Dwapar Yug and Kali Yug. This is the Kali Yug that is believed to have begun with the death of Krishna, in 3102 BC.

Gregorian

The most widely used calendar today for all civil purposes is the Gregorian calendar, and it was first introduced in February 1582 by Pope Gregory XIII, and so carries his name. It is a pure solar calendar that was introduced in an effort to reform the Julian Calendar, introduced in 53BC by Julius Caesar also introduced in order to reform the Roman Calendar in use at the time since 713BC.

The Julian calendar introduced an error of 1 day every 128 years, which was corrected by the Gregorian calendar. There is a leap year every four years but it is interesting to note that the years 1900, 2100, and 2200 are not leap years, however, the years 1600, 2000 and 2400 are leap years. Why? Well, according to rules of the Gregorian calendar, if a year can be evenly divided by 100, it is not a leap year unless it is also evenly divisible by 400!

But the Gregorian calendar is not so perfect itself and is considered to be off by about one day every 3236 years. The Gregorian calendar was first adopted in Italy, Poland, Portugal and Spain in 1582.