And this is another carved bone, this time from France, say approximately 11,000 BCE. Now the carving is becoming more sophisticated. Even so long ago people felt the need to harness the surrounding forces of nature and it has been the regular cycles of these forces of nature, observed in the passing of days, months and years, which have been used to measure time and which through the ages have given rise to the various calendars which mark the passing of time in the lives of each one of us. In the early days of humanity, it was the seasons, within the yearly cycle which determined the needs of the tribe and controlled the supply of natural food - food was plentiful in the summer and autumn, but there was no food at all to be had in the winter.