Calendar

Months
Found as far back as 30,000 BC, in Le Placard, France, the first calendar was carved on an eagle's bone, with clearly deliberate markings that recorded the cyclic nature of the moons (hence the word, "months", from "moons"). However, there wasn't much interest from the scientific community until another calendar, dated to be roughly 6,500 BC, was found in Ishango, rousing the interest of a certain Alexander Marshack to do research on the calendar of the ancients.

The Sun
The sun, too, has its own patterns to define the annual succession of the seasons. Although the moon is used to record the passing of each day, the sun, whose patterns change less frequently and less drastically, is normally used to record the seasons. As the ages passed, ancient man discovered that there was roughly 365 days to each change of the sun's pattern, and subsquently 365 days to a year. This was one of the more important discoveries, as it finally allowed man to plan ahead for the entire month, perhaps even the entire year, rather than living each day by day.

Measuring the Year

Items needed:
1) Flat horizontal surface
2) A straight stick planted vertically to the ground.

The flat surface could be prepared by water levelling, hand and eye or by rolling pebbles across the surface. To ensure that the stick is upright, use a plumb bob (a weighted string). After the apparatus is set up, a theoretical scientist could then find out the length of the year. The parabola could be traced and as the year goes by, the curves would move according to seasons and thus allowing the scientist to calculate out the number of days in a year. It would also help the scientist discover the precise time which month would have the longest and shortest days and when the turning point between the equinoxes occurred.