4 Apr
2011
4 Apr
'11
6:19 p.m.
From: Jerome H. Fine
Sent: Monday, April 04, 2011 5:49 PM
> Don North wrote:
> Actually I'd be more interested in Y1K support
since I am using
> an 11/34 as the navigational computer in my time machine, and it
> only goes back in time.
Already taken into account. The only question is how
far back?
While my initial start year was around 9999 BCE, I settled for the
year 1588 CE (= 1972 - 3 * 128). Since the Gregorian Calendar
started in 1582, there would not be any question of needing the
proleptic Gregorian Calendar dates (dates which would be in effect
if the Gregorian Rules had been used prior to 1582). However,
if you need all of the dates for positive years staring with 1 CE, that
can easily be accommodated.
You have forgotten to take into account the fact that the Gregorian
calendar was not adopted in by English speakers until 1752, by which
time an 11th day had to be dropped from the calendar. While the Catholic
countries in Europe adopted the Gregorian calendar in 1582, dropping 10
days in October, the English and their colonies took another 170 years,
and dropped 11 days in September of that year.
So any time-warping calendar program needs to take not only the date but
the location into account.
It is far better to use Julian days (not related to the Julian calendar
which the Gregorian revised), and calculate from there to dates on any
shorter-term calendar.
Rich Alderson
Vintage Computing Sr. Server Engineer
Vulcan, Inc.
505 5th Avenue S, Suite 900
Seattle, WA 98104
mailto:RichA at vulcan.com
mailto:RichA at LivingComputerMuseum.org
http://www.LivingComputerMuseum.org/