def showAllVoyagesInRange(self, start_datetime = '', end_datetime = ''):
        '''Shows all voyages for a current time period'''

        if start_datetime == '':
            print('Enter start date for time period')
            print()
            start_datetime = VoyageUI().getDateInput()


        if end_datetime == '':
            print('Enter end date for time period')
            print()
            end_datetime = VoyageUI().getDateInput()