%%
%%    FILE moon.tex
%%
\loadadvanced
\newcount\moonno
\def\firstmoon{\moonno=\Year
 \multiply\moonno by123685 
 \divide\moonno by10000
 \multiply\moonno by4\advance\moonno by-1
 \loop\moondate\ifnum\date<\yearbase
 \advance\moonno by1\repeat}
% Compute date for cycle quarter MOONNO
\def\moondate{{\count0=\moonno
 \lin 202.126.369+0.\count0=\count1
 \count6=0
 \lin 0.2.319+2907.\Sin\fac{3}
 \divide\count6  by1000
 \lin 365.249.86+7593.\id\fac{1}
 \divide\count6 by10\count7 =\count6
 \ifodd\moonno\quarters
 \else\fullornew\fi\global\date=\count7}
 \JDTtoL\message{\the\date}}
% Correction for full and new moon
\def\fullornew{\count6=0
 \lin -393.0.0+0.
 \divide\count1 by100000000 
 \advance\count6  by\count1
 \lin 0.628.300+6269.\Sin 
 \multiply\count6  by\count4
 \lin -7.-700.-369+  928.\Sin\fac{  -74}
 \lin  0. 628. 300+ 6269.\Sin\fac{ 1734}
 \lin  1. 256. 600+12539.\Sin\fac{   21}
 \lin  8. 328. 670+ 5341.\Sin\fac{-4068}
 \lin  8. 538. 220+-4597.\Sin\fac{   10}
 \lin  8. 956. 970+11610.\Sin\fac{  -51}
 \lin 16. 238. 589+-5526.\Sin\fac{   -4}
 \lin 16. 657. 340+10682.\Sin\fac{  161}
 \lin 16. 866. 890+  743.\Sin\fac{  104}
 \lin 17. 285. 640+16951.\Sin\fac{   50}
 \lin 17. 495. 190+ 7013.\Sin\fac{    4}
 \lin 24. 986.  10+16023.\Sin\fac{   -4}
 \lin 25. 195. 560+ 6084.\Sin\fac{   -6}
 \divide\count6  by10000
 \advance\count7 by\count6 }
% Correction for quarters
\def\quarters{\lin -393.0.0+0.
 \divide\count1  by100000000 
 \count6 =\count1  \lin 0.628.300+6269.
 \Sin\multiply\count6  by\count4 
 \lin -16. -29. -40+-4413.\Sin\fac{   40}
 \lin  -7.-700.-369+  928.\Sin\fac{  -47}
 \lin  -7. -72. -69+ 7198.\Sin\fac{  -30}
 \lin   0. 628. 300+ 6270.\Sin\fac{ 1721}
 \lin   1. 256. 600+12539.\Sin\fac{   21}
 \lin   8. 328. 670+ 5341.\Sin\fac{-6280}
 \lin   8. 538. 220+-4598.\Sin\fac{   21}
 \lin   8. 956. 970+11611.\Sin\fac{ -119}
 \lin  16. 238. 589+-5526.\Sin\fac{   -4}
 \lin  16. 657. 340+10682.\Sin\fac{   89}
 \lin  16. 866. 890+  743.\Sin\fac{   79}
 \lin  17. 285. 640+16952.\Sin\fac{    3}
 \lin  17. 495. 190+ 7013.\Sin\fac{    3}
 \lin  24. 986.  10+16023.\Sin\fac{   -4}
 \lin  25. 195. 560+ 6085.\Sin\fac{   -6}
 \count8=\count6\count6=28000
 \lin 628. 300. 373+ 6270.\Cos\fac{   -4}
 \lin   8. 328. 670+ 5341.\Cos\fac{    3}
 \count2=\moonno
 \advance\count2 by-1\divide\count2 by2
 \ifodd\count2\multiply\count6  by-1 \fi
 \advance\count6 by\count8
 \divide\count6  by10000
 \advance\count7  by\count6 }
% Events for phases.
% Uses PHASE (local).
\def\includemoons{\message{Including moons}
 {\firstmoon
\Month=12\Day=31\dayno\advance\date by1
 \count1=\date
 \loop\moondate\phase\ifnum\date<\count1
  \evday[\themoon]\advance\moonno by1
 \repeat}}
\def\phase{{\count0=\moonno
 \count1=\moonno
 \divide\count0 by4\multiply\count0 by4
 \advance\count1 by-\count0\relax
 \global\edef\themoon{\ifcase\count1
  New moon\or First quarter\or
  Full Moon\or Last quarter\fi}}}