Just something to consider about any electronic device, especially ones that are on an unfused, high current line. Lightening. Circuit breakers don't count as they are too slow acting. Unless you get a direct hit, the simple and cheaper mechanical timers are pretty immune. Manufacturers do consider power line spikes to varying degrees, but in any case, spikes and electronics don't get along well together. Another issue is wide temperature swings on electronic components if they are so exposed. I know they have a warranty but that is probably one year at most and anything after that, you eat it. Just my opinion.
Al