We’re getting towards the end of the year and in Mythos we’re talking about creating this “2019 Mythos Pin Up Calendar”, but what about calendars throughout time?
Did the Romans use a calendar like ours? And the Greek?
Let’s find out! Please enjoy a few historic trivia about calendars, and a nice Neil Sedaka song at the end, to get in the right mood.
First of course our own; the calendar we are currently using on Earth is the Gregorian calendar. It is named after Pope Gregory XIII, who introduced it in 1582. What was the main new feature of this calendar? February 29! Every four years we add this day, to keep in line with the seasons and the sun position. Note that not all 4 years are leap years! We skip centuries that are not divisible by 400, so 1700, 1800, and 1900 were not leap years, but 1600 and 2000 were!
Most Catholic countries introduced the Gregorian calendar right away, and many other countries followed, although some countries – with other religions – hesitated for centuries. Greece, for example, was the last European country that introduced the Gregorian calendar, in 1923. 
We regulate the entire world according the Gregorian calendar for logical reasons (schedules for flights, business, etc.), but there are about forty other calendars around the world, and six or seven still in use, particularly for determining traditional or religious dates, such as the Jewish calendar or the Islamic, Muslim, or Hijri calendar. 
The Gregorian calendar was introduced to correct the Roman calendar. In this calendar, known as the Julian Calendar named after Julius Caesar and introduced in the late first century BC, they also had leap years, but the leap day was inserted by doubling February 24 and – more importantly – they didn’t do the 400-year correction. So, if we would have lived according this calendar, we would be 13-days ahead by now.
By the way, the Romans were also the ones that added ‘January’ and ‘February’ to the calendar. In early Roman times, a year would start in March would last for 10 months; the remaining unorganized 50-day period was just called ‘winter’. 
The Maya calendar consists of several cycles or counts of different lengths. To track longer periods of time, they used the so called Long Count calendar. It is a count of days since a mythological starting point: August 11, 3114 BC (according the Gregorian calendar).
The Long Count calendar is not based on the sun position, but on a numeral system, based on the number “20” (with some exceptions for “18”), and each unit of a given position represented 20 times the unit of the position which preceded it.
Due to this nature, the Long Count calendar was capable of being extended to refer to any date far into the past or future. Maybe you remember that some proclaimed the end of the world on December 21, 2012. Misinterpretation of the Long Count calendar was the basis for a popular belief that a cataclysm would take place on that day: “The Maya calendar ends on that date, and so will the world”. The notion was false; The date was just an end-date of a 5,126-year-long cycle in that calendar. The next ‘fatal date’ will be October 13, 4772.  
The Egyptians also used a solar calendar with a 365-day year, but the year consisted of three seasons of 120 days each, based on state of the borders of the river Nile: akhet (Inundation), peret (Growth) and shemu (Harvest). The heliacal rising of Sothis returned to the same point in the calendar every 1,460 years (a period called the Sothic cycle). 
The Greeks were moon lovers; as early as the time of Homer, they appear to have been familiar with the division of the year into the twelve lunar months. Independent of the division of a month into days, it was divided into periods according to the increase and decrease of the moon. The month in which the year began, as well as the names of the months, differed among the states, and in some parts even no names existed for the months, as they were distinguished only numerically, as the first, second, third, fourth month, etc. 
So enough fun facts for now and back to our own calendar, and pin up challenge. To get inspirational, I leave you with a lovely song of Neil Sedaka