Thousands of years before the invention of the script, and the development of science, architecture and astronomy, men observed the nature, followed its cycles and tried to measure time.
The earliest calendars were created by observing the moon. Its circular route from new moon to full moon and back to the new moon is visible and comprises a short period of time. The moon's circular route takes 29.53 days.
A much longer circular route is made by the sun. Observation of the path of the sun comprises a longer period of accurate measurement of the position of the sun. The sun makes its circular path in 365.24 days, which is also the time in which nature makes its circular path (ripening of fruit, wildlife migration, sowing and reaping of crops, the changing of the seasons...), the time within which the circle is complete and a new round period starts.
It was not until the construction of large megalithic buildings where a solar beam at the winter solstice falls on a specific point, that one could follow the emergence and development of an astronomy calendar. Many civilisations had a round perception of time. Often, calendars were illustrated in a round form. The most well-known of these is an Aztec calendar of circular shape, carved in stone, with a diameter of nearly four metres, known as the Sun Stone. The calendar consists of five round records of the sun's path.
Calendar Round is the name of the Mayan calendar, where the circular 260-day and 365-day cycles intertwine and return to the starting point every 52 years.
Modern technology and smart phones enable us to use the round calendar again. Such a calendar is available to us with the CircleTime Application, where the annual round calendar offers much more than traditional calendars.