The Library Kids : Mayan Calendar, Aztec Calendar, Julian Calendar, Gregorian Calendar

There has been much speculation of what will happen to the world on December 21, 2012 (the winter solstice) due to the rumor the Mayan Calendar ends on that date. First of all, many people confuse the Aztec calendar with the Mayan Calendar. This is the Aztec Calendar:

http://en.wikipedia.org/wiki/File:Monolito_de_la_Piedra_del_Sol.jpg

According to wikipedia:

The calendar consisted of a 365-day calendar cycle called xiuhpohualli (year count) and a 260-day ritual cycle called tonalpohualli (day count). These two cycles together formed a 52-year "century," sometimes called the "calendar round". The xiuhpohualli is considered to be the agricultural calendar, since it is based on the sun, and the tonalpohualli is considered to be the sacred calendar.

The calendric year may have begun at some point in the distant past with the first appearance of the Pleiades (Tianquiztli) asterism in the east immediately before the dawn light.^[1] (See heliacal rising.) But due to the precession of the Earth's axis, it fell out of favor to a more constant reference point such as a solstice or equinox. Early Spanish chroniclers recorded it being celebrated in proximity with the Spring equinox.

The Mayan calendar is a different calendar and is described as follows:

According to wikipedia:

The essentials of the Maya calendar are based upon a system which had been in common use throughout the region, dating back to at least the 5th century BCE. It shares many aspects with calendars employed by other earlier Mesoamerican civilizations, such as the Zapotec and Olmec, and contemporary or later ones such as the Mixtec and Aztec calendars.^{[citation needed]} Although the Mesoamerican calendar did not originate with the Maya, their subsequent extensions and refinements of it were the most sophisticated.^{[citation needed]} Along with those of the Aztecs, the Maya calendars are the best-documented and most completely understood.^{[citation needed]}

By the Maya mythological tradition, as documented in Colonial Yucatec accounts and reconstructed from Late Classic and Postclassic inscriptions, the deity Itzamna is frequently credited with bringing the knowledge of the calendar system to the ancestral Maya, along with writing in general and other foundational aspects of Maya culture.^[3]

The Maya calendar consists of several cycles or counts of different lengths.

The 260-day count is known to scholars as the Tzolkin, or Tzolk'in in the revised orthography of the Academia de las Lenguas Mayas de Guatemala.^[4] The Tzolk'in was combined with a 365-day vague solar year known as the Haab' to form a synchronized cycle lasting for 52 Haab', called the Calendar Round. Smaller cycles of 13 days (the trecena) and 20 days (the veintena) were important components of the Tzolk'in and Haab' cycles, respectively. The Calendar Round is still in use by many groups in the Guatemalan highlands.

http://en.wikipedia.org/wiki/File:East_side_of_stela_C,_Quirigua.PNG

The last pharaoh of Egypt was Caesarion. He was born on June 23, 47 BC (around the summer solstice) and was allegedly murdered on August 23, 30 BC. He reigned with his mother, jointly from September 2, 44 BC to his alleged death. Caesarion lived in Rome for two years of his life and returned back to Egypt with his mother after Caesar was assassinated on March 15, 44 BC (The Ides of March). Plutarch claimed that Caesarion escaped to India and was not killed. Octavian took over the rulership of Egypt and Rome in 30 BC.

The Julian calendar and Gregorian calendar that we use today are based on his birth. It was designed for him under commission of his father, Julius Caesar and his rulership began on September 02,44 BC. Julius Caesar reformed the Roman Calendar in 46 BC and it had a regular year of 365 days divided into 12 months. A leap day was added in February every four years. The Gregorian calendar (24 February 1582) was added to compensate with differences between it and a tropical solar year. It is also interesting to note that January 01 was not always the start of the new year, it was around September 01. The Coptic Calendar, also called the Alexandrian Calendar, has its new year on September 11 and the calendar is based on the old Egyptian calendar. It is still used by the Coptic church, today.

It appears there is about a 45 year difference between today’s calendar start date (from year 01 BC to 01 AD) and the start of Caesarian’s calendar based on birth of deities. However, this could be a mistake done on purpose to hide the true identity of the last pharaoh, Caesarion.