Prompted by a technical discussion about date formats, I dug out a copy of David Ewing Duncan's superlative "Calendar: Humanity's Epic Struggle to Determine a True and Accurate Year", and found the author's blog.
As for the automated manipulation of the calendar, a colleague pointed out this tit-bit o' unix fun:
(salim@xampanyet) ~ % cal -3 9 1752
August 1752 September 1752 October 1752
Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa
1 1 2 14 15 16 1 2 3 4 5 6 7
2 3 4 5 6 7 8 17 18 19 20 21 22 23 8 9 10 11 12 13 14
9 10 11 12 13 14 15 24 25 26 27 28 29 30 15 16 17 18 19 20 21
16 17 18 19 20 21 22 22 23 24 25 26 27 28
23 24 25 26 27 28 29 29 30 31
30 31
Just as we find the railroads behind the standardization of clock time, we might credit the Church for the standardization of the calendar, done so that everyone can hunt Easter eggs at the same time.