epoch Prime

[salvomic]

(01-05-2018 07:30 PM)Dieter Wrote:  ... Simply calculate the Julian day number for two dates and you're done.

...

Dieter

Something like the formula used in my Astrolabio (Effemeridi), after Astrolab by Marcel Pelletier, maybe...

Code:


EXPORT julianDay(lista)
// lista like dateshortlist
BEGIN
  LOCAL y,m,d,a,b, JD;
  y:=lista(1);
  m:=lista(2);
  d:=lista(3);
  IF (m=1 OR m=2) THEN
  y:=y-1;
  m:=m+12
  END;
  IF y*100+m+d>=158225 THEN
  a:=IP(ABS(y/100));
  b:=2-a+IP(a/4);
  ELSE
  b:=0
  END;
  JD:=IP(365.25*(y+4716))+IP(30.6001*(m+1))+d+b-1524.5;
  RETURN JD;
END;

where "lista" is based on

Code:


dateshortlist:= MAKELIST(X,X,1,3);

and so on...

Salvo