Represent estimated day/month/year in ancient dates

[kmuncie]

Need to be able to represent a specific date in time and classify as estimated.

e.g. - it book on Adam: " That was in the year 4026 B.C.E. It was likely in the fall of the year, for mankind’s most ancient calendars began counting time in the autumn around October 1, or at the first new moon of the lunar civil year."