2nd argument: Multiple calendars
The calendar, as an instrument that allows us to order the years (the point at which the Earth finishes circling the Sun) has also lent itself to various historical corrections. In order not to bore you so much with them, I only want to delve into the most important ones.
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The Roman calendar: established by Numa Pompilius; It consisted of a lunar year, first of 10 months and then of 12, with some irregular changes. -
The Julian calendar: established by Julius Caesar; It consisted of a solar year of 365 days and 6 hours, where a leap day was added every 4 years.
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The Gregorian calendar: used today and established by Pope Gregory XIII; It consists of a solar year of 365 days, where every 4 years a leap day is added; except years ending in '00', which are only leap years if they are divisible by 400; The most radical aspect of the Julian-Gregorian transition was that Pope Gregory
As if this were not enough, and returning to the issue of adjustments, it is worth remembering that the real year is 365.2422 days, resulting in the Gregorian calendar still having an error of 0.0003 days per year; Added to this is that both the length of the real year and the Earth's rotation change slowly and unpredictably, so there will always be a margin of error. So, as a second conclusion, even assuming that our time scale governed by the birth of Jesus Christ is valid, both the calendar, the margins of error and the Earth's rotation have undergone enough changes to think that we are not really on the day, month and year that we believe we are, but on an approximate date (earlier or later) that cannot be determined with certainty.
***The third and final argument is the simplest, but once again, it will be raised "assuming" for a moment that even with the current time scale, calendar adjustments, Earth rotation and margins of error, the date we believe ourselves to be on is correct.
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