Very interesting article for those who are interested in the history of midwifery.
"New research suggests that a calendar based on the movement of planet Venus was used in the daily lives of people in ancient Aegean civilizations about 4,000 BC, and may have even been used to track milestones during pregnancy. Neolithic objects in the shape of ‘frying pans’ that were found in Greece, were decorated with concentric circles, spirals, radial patterns and sometimes rowing vessels. Professor of space physics, Minas Tsikritsis, suggested at the 21st International Conference of SEAC (Societe Europeenne pour l’Astronomie dans la Culture) that the objects were used as calendars to perform astronomical calculations of the orbits of Venus, Jupiter, Mars and Sun. The use of the frying-pan object, whose shape is believed to be symbolic, was used to associate activities and events in their life with the environment and astronomical events. Furthermore, according to Professor Tsikritsis, it appears that during the Neolithic era the ancient Greeks not only knew that Earth requires 365 days to make a complete circuit around the Sun, but also that Venus needs 584 and Jupiter 399. The interesting thing is that it looks that the movement of planet Venus was correlated to the biological cycle of pregnancy. Planet Venus (related to Goddess Aphrodite) appears before the sunrise for 263 days (approximately 9 moon months) and another 265 days after the sunset. So half of Venus cycle is approximately 9 months which coincides with the biological cycle of pregnancy. Adding to that, it can be seen that on some of the objects triangles and other symbols were engraved next to specific days of the calendar, and some even had engravings in the shape of the female uterus. This suggests that such a calendar was used by women to determine if they were pregnant or not, as well as tracking the milestones of their pregnancy. It seems that people of this Era in Greece had advanced astronomical knowledge and used multiple complex calendars for many different reasons, including the famous Antikythera Mechanism."