Julian and Gregorian Calendar with Moon Phases

Author: Valentin Hristov, Sofia, Bulgaria
E-mail: valhrist@bas.bg, valhrist@gmail.com
Web page: www.math.bas.bg/complan/valhrist/mystuff.htm

The calendar consists of three parts - inner, middle, and outer.

Cut each part along the outside lines.
Cut the two "windows" on the outer part.
Glue as a cylinder each of the parts.
Slip consecutively the middle and the outer part over the inner one.

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To have the proper month calendar with days of the week (outer and
middle parts) it is needed to make only one move:

Put the letter corresponding to the month at the crossing of the
  horizontal line with the full century and the vertical line with the
  year in the century. Be sure that you use the proper style - Julian
  (old) or Gregorian (new).

LEAP YEARS are those which are divisible by 4.
EXCEPTIONS from this rule are only the exact centuries in the Gregorian
  (new) style which are NOT divisible by 400 (1700, 1800, 1900, 2100,
  2200, 2300 are not leap years, but 1600, 2000, 2400 are leap years).
Leap years, exact centuries, and January and February in leap years are
  indicated with CAPITAL BOLD letters (JAN, FEB).

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To have the proper placement of the dates in a month against the MOON
 PHASES (middle and inner parts), at least two consecutive moves are
 needed. They use the visible line of gluing of the inner part, which
 will be called "new moon line" (contains black filled circle):

- Slide the middle part over the inner one so that the arrow on the
   upper edge of the gluing line stands against the "new moon line" at
   the level of the full centuries (Julian or Gregorian style) on the
   inner part.
  Read and remember the correction corresponding to the needed century.
  For convenience 20 Gregorian is at the "new moon line" with no
   correction, so this step can be skipped for our century.
- Put the remembered correction against the "new moon line" at the level
   of the years in the century.
  Read and remember the correction corresponding to the needed year in
   the century.
- Put the remembered correction against the "new moon line" at the level
   of the months.
  Read the last correction against the needed month.
  Be careful with January and February, because they are at different
   places for ordinary and leap years.
- Put the last correction against the NEW MOON SIGN.
  In fact the last correction gives the date of the new moon in the
   desired month and you have the moon phases for all dates in the
   month.

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The file calmoon.bas which produces the CALENDAR WITH MOON PHASES can be
edited with any ASCII editor. It is a macro for the DeltaCad program
with a demo version which can be downloaded from www.deltacad.com.
Printing the three landscape pages with one and the same width needs
fixing of three different printing areas which is time consuming for the
user. Therefore I decided to include also a non-standard approach.

The three sheets are included for printing on HP LaserJet or compatible
printer as .prn files. Open the "MS-DOS Prompt" window (command.com or
cmd.com), type and execute the following commands:
  copy calmoon1.prn prn /b
  copy calmoon2.prn prn /b
  copy calmoon3.prn prn /b

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If you want to print directly from DeltaCad on a printer, which is not
compatible with LaserJet, then go through the "Options-Macro-Run" menu.
In the File menu choose "Set print region".
The three areas for printing have equal Left and Right boundaries:
-1.1  and  10.
The corresponding Bottom and Top boundaries are the following:
inner  part    -0.1  and   6.9
middle part    -6.1  and  -0.9
outer  part   -11.1  and  -6.4
Choose the Landscape printing.

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Recently (October 2008) I decided to produce the three sheets as .pdf
files. This makes the printing much easier.

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In the code of the macro I used only the linear part of the formula for
the "MEAN NEW MOON" from www.wikipedia.com for GMT. The phases of the
REAL MOON could differ from the shown ones by +/- one day. A bigger
difference could appear if you use the moon calendar at a place with
big longitude (far away from Greenwich - up to additional +/- 12 hours
error).

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HAVE A FUN WITH THE MOON PHASE CALENDAR !!!

