The calendar in use before King Solomon became sea-faring partners with Hiram of Tyre was the sun-based model described in first the Book of Enoch, then the Book of Jubilees. Enoch was first, being an updated version of the description of the calendar that was given to the world long before Noah. It contained 360 days “exactly” and had no intercalations (days or weeks inserted at given intervals to keep it on track with the sun).
Then the earthquake in the days of Uzza caused 5.25 days to be added to the year, which resulted in Hezekiah having the astronomer-priests in the temple re-calculate the calendar according to the seasons and make adjustments. The perturbations had changed the earth’s orbit in such a way that the number of days in the year had become unstable. Spring would come earlier or later in the count of days according to the stretch in the elliptical orbit of earth. The other nations, from Egypt to the priests of South America, to China, simply added five days on to the end of the year. Hezekiah was far more particular, demanding that each Spring on the calendar be within three days of the actual event so that the farmers and herders could keep track of their accustomed activities. They were able to do so by adding – intercalating – weeks at specific intervals.
These weeks were not described in the Book of Enoch, although the original character of the times were written into the law before the land was settled. For instance, Moses wrote into the law that the land, the cattle, and the people were to rest every seventh year, and that trumpets were to be blown in a specific pattern or melody to signify the start of that year of rest, but he never said anything about adding a week to the calendar, which was done in the days of Hezekiah after the great earthquake. Moses never said anything about adding two weeks during the 50th year, the Year of Release, either. Further, there was no mention of animal sacrifices, as the temple was neither conceived nor built until the Israelites began their journey in the wilderness, and which has been roundly criticized by prophets and priests ever since.
What we do know is that the quarterly days of Spring (when every calendar on earth started before Pope Gregory XIII changed it to January to please the Roman Senate), Summer, Autumn, and Winter were added during the days of the flood, along with the seventh and 50th years,
We deduce that the seventh and 50th years were added during the flood, because every “holy” day, month, or year marks a stretch in earth’s orbit that added days to the calendar that were not there before. Additional evidence is that the calendar in every settlement after the dispersion of Noah’s family was in chaos, and didn’t settle down until the last days of Noah’s life when the Zodiac was recalculated and a new universal calendar was given by Noah to his descendants to replace the 12-month, 600-day calendar that was active before that event.
All of this is a bit much to chew on thought-wise at one sitting. It would be best to take them one bite at a time, like eating the proverbial elephant, so they can be absorbed in comfort and in their proper importance, or lack thereof, as the case may be. And so the posts shall be in tidbits, a little here, a little there, here some subject, there some idea, as time goes on.