When in doubt, put it to the t-test.
Does the difference between Julian and Gregorian calendars matter?(Over that time scale, probably not. I think the difference is 3 days over 400 years...)I compute 79 years.
since there's no "year zero" does that affect the answer? or is there a year zero - i wasn't around back then.
It's 79 years and 365 days. I'm trying to figure out whether the leap year situation gets screwed up in the switch, but I think that's one day short of 80 years. Of course, this is calculating back what would have been days x and y in those years, which were not denominated thus at the time.The older Greek calendars were out of use by then, so I think we can safely stay in the Roman calendar.