As long as we are worried about problems with potential Y5K bugs, should
we not also worry about Y5B problems?

http://www.y5b.com/

Mark Landin wrote:
>
> Copied from the sci.space.news newsgroup:
>
> American Institute of Physics
>
> Contact:
> David Book
> University of Maryland
> (301) 405-7580
> [log in to unmask]
> www.astro.umd.edu/people/book.html
>
> Geoff Chester
> US Naval Observatory
> (202) 762-1438
> [log in to unmask]
> www.usno.navy.mil
>
> Rory McGee
> American Institute of Physics
> (301) 209-3088
> [log in to unmask]
>
> February 25, 2000
>
> The Y5K bug? Hurdling the leap day problem
>
> Leap day may simply seem like a novelty that comes once every four
> years,
> but without it, the seasons would quickly get out of whack. Even with
> the
> extra day, we may be headed for problems down the line.
>
> Our modern "Gregorian" calendar has been used by the Roman Catholic
> Church
> since 1582 and was adopted by England in 1752. But University of
> Maryland
> physicist David Book points out there are still a couple of problems
> with
> the system. In a recent letter to the Washington Post
> [http://www.washingtonpost.com/wp-srv/WPlate/2000-01/12/027l-011200-idx.html],
> he mentions one he calls the "Y5K problem."
>
> Our modern calendar is designed with the seasons in mind. It is
> supposed to
> match up with what a farmer considers a year, or the time between two
> vernal equinoxes. (The vernal equinox, which marks the start of
> spring,
> occurs on the day in which the Sun rises over Earth's equator.) Using
> this
> definition, a year is 365.2422 days. By adding leap years at regular
> intervals,
> our modern calendar sets an average year at 365.2425 days -- very
> close to
> the length between vernal equinoxes but with a slight discrepancy of
> 0003
> days.
>
> The discrepancy may be small, but it adds up. Geoff Chester, with the
> US
> Naval Observatory (whose Time Service Department keeps the official
> time
> for the United States) points out that we are already "3 hours ahead
> of what
> the seasons tell us." If we do nothing, our calendar will be a day
> ahead of
> schedule in 2915 years. Book calls this the "Y5K problem," because it
> would
> occur roughly around the year 5000.
>
> Book also says that we need to think about fixing the problem now.
> "These
> errors accumulate. The longer we wait to make the correction, the more
> disruptive it will be." There are even suggestions floating around for
> how
> to make the change.
>
> Chester says he's seen "one or two proposals to refine the Gregorian
> calendar
> by one leap day." In one such proposal, he explains that we would
> continue
> with the "normal" Gregorian rules with one exception -- years
> divisible by
> 4000 (such as 4000 AD and 8000 AD), which are leap years under the
> present
> system, would become ordinary years. "Thus, you'd have 969 leap days
> every
> 4000 years," says Chester, "resulting in an average calendar year of
> 365.24225 days." With this method, Chester days "we won't get a full
> day
> out of kilter for some 15,000 years." Whether or not the Gregorian
> calendar
> will actually be changed, however, only time will tell.
>
> ADDITIONAL LEAP DAY WEBSITES:
>
> * Royal Observatory Greenwich Page on Leap Year
>   http://www.rog.nmm.ac.uk/leaflets/leapyear/leapyear.html
> * US Naval Observatory Page on Leap Year
>   http://aa.usno.navy.mil/AA/faq/docs/leap_years.html
>
> ---
> Andrew Yee
> [log in to unmask]