Yeah. I'm not sure of the technology used in France, but in Belgium we get this: https://en.wikipedia.org/wiki/Zellweger_off-peak https://en.wikipedia.org/w

Yeah. I'm not sure of the technology used in France, but in Belgium we get this: https://en.wikipedia.org/wiki/Zellweger_off-peak https://en.wikipedia.org/wiki/Zellweger_off-peak It actually signals both the strict off-peak times (from 22:00 to 07:00 as well as Saturday and Sunday) and separately, a "night programme" that is variable and used to manage to grid more efficiently. Apparently, there are many different signals that go over the wire, and houses are more or less randomly tuned to one of them. The strict times are used by the counter itself to know how to count usage, and the night programme is used for the appliances.