%%
%%    FILE sun.tex
%%
\loadadvanced
\def\linY#1.#2.#3+#4.{{\count0=\Year
 \multiply\count0 by1000\count1=0
 \lin #1.#2.#3+#4.
 \global\date=\count1}\JDTtoL}
% (local)
\def\includeseasons{%
 \message{Including seasons}
 \linY 365.242.365+ 79573.\evday[Spring]
 \linY 365.241.628+172405.\evday[Summer]
 \linY 365.242.045+266014.\evday[Fall]
 \linY 365.242.756+355784.\evday[Winter]}