Calculating Julian dates
Welcome to Code Review,

I do not know how to solve your problem, however, your code could use polishing.


Magical constants; your code is littered with them, use constants instead
Undocumented magical constants, I can guess what 365 or 12 is used for, other constants like 32083 could use a comment or could show the calculation of how you got there
Naming; todDay, todMonth and todYear are terrible names
Naming; at, ty and mt are even worse
Casing; be consistent, you mix underscores with casing and even your casing is not consistent ( calc_julianToday &lt;> calc_juliandate )
Indenting! Your indenting is all over the place and distracts the reader
Repeating / DRY;


I do not write C++ but can you not write calc_julianToday() as

int julian::calc_julianToday()
{
  time_t t = time(0);
  struct tm *now = localtime( &amp;t );
  return julToday =  calc_juliandate( now-&gt;tm_mday, now-&gt;tm_mon+1, now-&gt;tm_year+1900 ) ;  
}