anchor.diff:  
               day = floor(day_fraction - this%month_start(month)) + 1
               year = year + this%year_zero
  -
  +            mjd = mjd - this%hour_zero/24.0
           end if
   
           !------------------------------------------------------------
  
positive.code:         ! Calculate the hour/minute/second for any calendar
          !
          !------------------------------------------------------------
          day_fraction=mod(mjd,1.0)
          hour=floor(day_fraction*24)
  
          day_fraction=day_fraction*24-hour
          minute=floor(day_fraction*60)
  
          day_fraction=day_fraction*60-minute
          second = nint((day_fraction-(24d0*60*1d-5))*60)
  
      end subroutine calendar_date
  
  
negative.code:             date_to_mjd = date_to_mjd - gregorian_julian_day(this%year_zero, this%month_zero, this%day_zero, this%hour_zero, 0, 0)
  
          else if (this%calendar==NOLEAP) then
              date_to_mjd = (year*365 + this%month_start(month)-1 + day-1 + (hour + (minute+second/60d+0)/60d+0)/24d+0) &
                           - (this%year_zero*365 + this%month_start(this%month_zero)-1 + this%day_zero-1 + (this%hour_zero)/24d+0)
          else if (this%calendar==THREESIXTY) then
              date_to_mjd = (year*360 + this%month_start(month)-1 + day-1 + (hour + (minute+second/60d+0)/60d+0)/24d+0) &
                           - (this%year_zero*360 + this%month_start(this%month_zero)-1 + this%day_zero-1 + (this%hour_zero)/24d+0)
          end if
  
      end function date_to_mjd
  