Would you reference the source of this information as I would be interested.
It is my understanding that the various peoples had their own calendars.
The Egyptians, Babylonians,Hebrews,; Chaldeans , Medes, Persians, Greeks Romans all had their calenders which varied to some degree.
The Hebrews was based on a thirty day month and a 360 day year at the time mentioned.
It under went a change or adjustment around 1400-1300 BC as did most others around this time for reasons unknown but they all seem to acknowledge an increased number of days in a cycle.