code: private ProjectCalendar getResourceCalendar(Integer calendarID)
     {
        ProjectCalendar result = null;
        if (calendarID != null)
        {
           ProjectCalendar calendar = m_calMap.get(calendarID);
           if (calendar != null)
           {
              //
              // If the resource is linked to a base calendar, derive
              // a default calendar from the base calendar.
              //
              if (!calendar.isDerived())
              {
                 ProjectCalendar resourceCalendar = m_project.addCalendar();
                 resourceCalendar.setParent(calendar);
                 resourceCalendar.setWorkingDay(Day.MONDAY, DayType.DEFAULT);
                 resourceCalendar.setWorkingDay(Day.TUESDAY, DayType.DEFAULT);
                 resourceCalendar.setWorkingDay(Day.WEDNESDAY, DayType.DEFAULT);
                 resourceCalendar.setWorkingDay(Day.THURSDAY, DayType.DEFAULT);
                 resourceCalendar.setWorkingDay(Day.FRIDAY, DayType.DEFAULT);
                 resourceCalendar.setWorkingDay(Day.SATURDAY, DayType.DEFAULT);
                 resourceCalendar.setWorkingDay(Day.SUNDAY, DayType.DEFAULT);
                 result = resourceCalendar;
              }
              else
              {
                 //
                 // Primavera seems to allow a calendar to be shared between resources
                 // whereas in the MS Project model there is a one-to-one
                 // relationship. If we find a shared calendar, take a copy of it
                 //
                 if (calendar.getResource() == null)
                 {
                    result = calendar;
                 }
                 else
                 {
                    ProjectCalendar copy = m_project.addCalendar();
                    copy.copy(calendar);
                    result = copy;
                 }
              }
           }
        }
  
        return result;
     }
docs: Retrieve the correct calendar for a resource.
  
  @param calendarID calendar ID
  @return calendar for resource