Ever had your day lengthened by 4.8 hours? This was a clock that D had got for me as a gift in the US. It tells the time in binary and gets its power from a step-down AC transformer. That alone should have been warning but I brought it from the US to use in my Singapore office. Check out the video for the full deal.
Here's an example of how AC frequency can utilized by ICs for timing purposes.
tl;dr The 60 Hz power line frequency is often used to drive timing in US clocks. Consider this before plugging a US clock into a 50 Hz system.
