The HH Calendar is also very similar to Irv Bromberg's "Symmetry Calendar". I would be delighted if Irv's calendar should be adopted.
Attention is also drawn to the article "The Calendar of the Future. A World Calendar wtih Leap Week," by Josef Suran (1998, Vistas in Astronomy, 41, 493), and important references therein. Suran indicates that the notion of a leap-week calendar was first introduced in 1926 by M. P. Delaporte.
David Landau has kindly drawn my attention to an even OLDER calendar of this type, the
I am told that the source of this calendar is two books written during the Second Temple Period: "1 (the Ethiopic Book of) Enoch" and "Jubilees." Both books have survived extant only in Ge'ez, the liturgical language of the Ethiopian Church.
Phases of the Moon are calculated using the program given in "Numerical Recipes in Fortran," by W. H. Press, S. A. Teukolsky, W. T. Vetterling, and B. P. Flannery, 1992, (New York: Cambridge). This was checked against the Voyager planetarium program; agreement seems to be to about a third of a day, by spot checking. This should be adequate for most purposes.
Julian Day is calculated using formulas given by Steve Wolfram.
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