code: function cloneSchedule(sched) {
      var clone = {}, field;
  
      for(field in sched) {
        if (field !== 'dc' && field !== 'd') {
          clone[field] = sched[field].slice(0);
        }
      }
  
      return clone;
    }
docs: Returns a deep clone of a schedule skipping any day of week
  constraints.
  
  @param {Sched} sched: The schedule that will be cloned