code: public ProjectCalendar getCalendar()
     {
        ProjectCalendar calendar = null;
        Resource resource = getResource();
        if (resource != null)
        {
           calendar = resource.getResourceCalendar();
        }
  
        Task task = getTask();
        if (calendar == null || task.getIgnoreResourceCalendar())
        {
           calendar = task.getEffectiveCalendar();
        }
  
        return calendar;
     }
docs: Retrieves the calendar used for this resource assignment.
  
  @return ProjectCalendar instance