anchor.diff:        return this
       }
       Conference.prototype.addProgramEvent = function addProgramEvent(program_event) {
  -      this.programevents.push(program_event)
  +      this.program_events.push(program_event)
         return this
       }
       Conference.prototype.removeProgramEvent = function removeProgramEvent(program_event_name) {
  -      spliceFromArray(this.programevents, this.getProgramEvent(program_event_name))
  +      spliceFromArray(this.program_events, this.getProgramEvent(program_event_name))
  +      return this
  +    }
  +    Conference.prototype.addImportantDate = function addImportantDate(important_date) {
  +      this.important_dates.push(program_event)
  +      return this
  +    }
  +    Conference.prototype.removeImportantDate = function removeImportantDate(important_date_name) {
  +      spliceFromArray(this.important_dates, this.getImportantDate(important_date_name))
         return this
       }
   
  
positive.code:       return this.passes.find(function (item) { return item.name === pass_name })
      }
      Conference.prototype.getProgramEvent = function getProgramEvent(program_event_name) {
        return this.programevents.find(function (item) { return item.name === program_event_name })
      }
  
      //- MORE PROTO FUNCTIONS
  
negative.code:       self.pass_periods  = []
        self.passes        = []
        self.registration  = {}
        self.program_events = []
        self.important_dates = []
      }
  
      //- SETTER FUNCTIONS
  