History of the calendar
Artifacts from the Paleolithic suggest that the moon was used to reckon time as early as 6,000 years ago. Lunar calendars were among the first to appear, with years of either 12 or 13 lunar months (either 354 or 384 days). Without intercalation to add days or months to some years, seasons quickly drift in a calendar based solely on twelve lunar months. Lunisolar calendars have a thirteenth month added to some years to make up for the difference between a full year (now known to be about 365.24 days) and a year of just twelve lunar months. The numbers twelve and thirteen came to feature prominently in many cultures, at least partly due to this relationship of months to years. Other early forms of calendars originated in Mesoamerica, particularly in ancient Mayan civilization. These calendars were religiously and astronomically based, with 18 months in a year and 20 days in a month, plus five epagomenal days at the end of the year.The reforms of Julius Caesar in 45 BC put the Roman world on a solar calendar. This Julian calendar was faulty in that its intercalation still allowed the astronomical solstices and equinoxes to advance against it by about 11 minutes per year. Pope Gregory XIII introduced a correction in 1582; the Gregorian calendar was only slowly adopted by different nations over a period of centuries, but it is now by far the most commonly used calendar around the world.
Steatopygia is the state of having substantial levels of tissue on the buttocks and thighs. This build is not confined to the gluteal regions, but extends to the outside and front of the thighs, and tapers to the knee producing a curvilinear figure. The term is from the Greek stéar (στέαρ), meaning "tallow",  and pugḗ (πυγή), meaning "rump". Steatopygia, a genetic characteristic leading to increased accumulation of adipose tissue in the buttock region, is most notably (but not solely) found among the Khoisan of Southern Africa. It has also been observed among Pygmies of Central Africa and also the Andamanese people, such as the Onge tribe in the Andaman Islands. This genetic characteristic is prevalent among women but occurs to a lesser degree in men.Steatopygia would seem to have been a characteristic of a population which once extended from the Gulf of Aden to the Cape of Good Hope, from which peoples the Khoisan and Pygmies may be remnants. Among the Khoisan, it begins in infancy and is fully developed by the time of the first pregnancy.It has been suggested that this feature was once more widespread. Paleolithic Venus figurines, sometimes referred to as "Steatopygian Venus" figures, discovered from Europe to Asia presenting a remarkable development of the thighs, and even the  prolongation of the labia minora, have been used to support this theory. Whether these were intended to be lifelike, exaggeratory, or idealistic is unclear.