The creation calendar is found in the book of Enoch. Chapters 72 - 83 contain the properties of the heavenly luminaries as written on the heavenly tablets and described to Enoch by the angel Uriel.
The sun rules over the other time keeping luminaries of the heavens with the star constellations that witness to it. The sun first enters through the fourth gate, which is described as the major gate. This is a major gate because it contains two important time keeping elements of the calendar year. These are the spring and fall equinoxes which determine the beginning and middle of the calendar year. The spring equinox (March 20) begins the year as a marker which Enoch calls the leaders of the seasons. The first chief of thousands or the constellation Aries (March 21) begins the count of days on the day following the spring equinox. From this point we count three months of thirty days each. The second seasonal leader is the summer solstice followed by three months of thirty days each. The third seasonal leader is the fall equinox which also comes out of the fourth gate and is followed by three months of thirty days. The final seasonal leader is the winter solstice, which is followed by three months of thirty days each.
The Seasonal Leaders and Chiefs of The Thousands
The four markers or seasonal leaders are not counted in the months, but totaled in the number of days of the year, bringing the count to three hundred sixty, plus four days. These markers or four leaders of the seasons are also ordained as memorials to Noah and will always fall on a seventh day sabbath, if you don't pin the sabbath to the roman calendar day of Saturday aka Saturnalia.
The Chiefs of Thousands consist of the twelve constellations. These determine the character of the months along with the Captains of the three hundred sixty which determine the character of the days of the months.
The calendar is self sustaining and self correcting, needing no involvement by man. The timing of the spring equinox using UTC + 2 hours or Israeli Standard Time will determine if a day needs to be added.
All Miqra, sacred appointed meeting times, annual Sabbaths, etc. are determined from the first day of the year. The first seventh day is the begining of the weekly sabbaths. This invalidates the pinning of the seventh day Sabbath to a Saturday because the equinox cycles through the days of the Roman calendar week as the years progress. This also invalidates any theory of a fourth day of the week start. For more information see the link https://www.facebook.com/groups/179513092255225/