/* Compute the Hour, Minute, and Seconds from the julian day number.  */
static void computeHMS(DateTime *p)
/* Compute the Hour, Minute, and Seconds from the julian day number.  */
static void computeHMS(DateTime *p)
{
  int s;
  if( p->validHMS ) return;
  computeJD(p);
  s = (int)((p->iJD + 43200000) % 86400000);
  p->s = s/1000.0;
  s = (int)p->s;
  p->s -= s;
  p->h = s/3600;
  s -= p->h*3600;
  p->m = s/60;
  p->s += s - p->m*60;
  p->validHMS = 1;
}