by external influences

Clocks with attached or built-in means operating any device at preselected times or after preselected time-intervals > Mechanisms continuously running to relate the operation(s) to the time of day > with provision for automatic modification of the programme, e.g. on Sunday > by external influences

Clocks with attached or built-in means operating any device at preselected times or after preselected time-intervals (if restricted to producing acoustic time signals by electrical means G04C21/00) > Mechanisms continuously running to relate the operation(s) to the time of day > with provision for automatic modification of the programme, e.g. on Sunday > by external influences