Variable Earth Orbits & Solar Years
The orbit of Earth enlarged at least five times since being scavenged by Flare-Star Saturn c. -10,900 -- in c. -3147, -2349, -2193, -1492 and -747. (Cook, Appendix B, "Celestial Mechanics")
"In the thousands of years before 3147 BC the Earth's orbit was determined by the path which Saturn took around the Sun. But apparently the Sumerians kept a count of days during this period, or at least years. It is doubtful if either they or anyone else kept a calendar, or even felt the need to. The Sumerians (actually, their predecessors in Northern Mesopotamia) had been keeping accounts of agricultural products since 8000 BC [...]The Olmecs started counting years in 8347 BC, calling this year the 'first creation.'" (Cook, Appendix A)
Each time the Earth reached a different location from the Sun, it needed to adjust its charge level, and plumes of plasma extended up from the magnetic poles, lasting years.
The massive flood from the North Pole in c. -3147 was the most monumentally disruptive event in history. All the previous celestial displays had been well away from Earth, and could be neglected. The global flood of c. -3147, the new solar orbit and a consequent sudden elongation of the solar year changed all of that. Here was a distinct separation between "before" and "after," and it is little wonder that many people now show a serious concern with the passage of time, and begin keeping detailed tallies of days and years. (Cook, Appendix A)
Within fifty years of c. -3147, the Egyptians start an annual record of Gods or God-pharaohs. The calendar is annual, and years are named after religious festivals or other accomplishments. The years are without notation of seasons or months (there was no Moon orbiting Earth as yet).
The city of Kish in Mesopotamia similarly keeps track of Gods or God-kings by "years" (or some indeterminate measure of time). In only one instance a "month" is indicated in the record, but it seems to be an error, or may have been meant to signify a fraction of a year and was added at a much later date.
The Mesoamerican predecessors of the Maya were counting in Tuns ("stones"), which are years, and in Katuns, which are twenty-year periods, and soon in a larger measure of 400 Tuns, known (to us) as a Baktun. Certainly a record of years was kept, likely in terms of the larger blocks of 20 years and 400 years -- for in the 16th century AD the Maya 'Chilam Balam' will be able to correctly specify the Katun of all celestial events since c. -3147 that we know of from the eastern Mediterranean myth-histories.
From China we get a clearer indication of an archaic calendar system, but of course as remnants retained at later ages. China seems to have had a calendar based on dividing the 240-day year into four seasons of 60 days each. China, unlike Mesoamerica, Egypt, and Mesopotamia, had distinct seasons. This division of the year into 60-day periods remained a standard for 5000 years. Both the four seasons and the 60-day periods remained in use. Even after the Moon arrived in c. -2349, the months were still associated with these 60-day seasonal divisions. (Cook, Appendix A)