It may not be used so much for clocks now, but you can still buy cheap timed power switches that use this method. For example: https://www.argos.co.uk/product/

It may not be used so much for clocks now, but you can still buy cheap timed power switches that use this method. For example: https://www.argos.co.uk/product/5440524 https://www.argos.co.uk/product/5440524