Not if you use it. It's cold afterwards so no standing loss. You're still thinking in terms of keeping it warm and not warming it when you need it.Not sure what you're talking about, for a geyser you're heating up all the water in the tank to the temperature, that water will have a standing loss.
If you're talking about tankless, sure, I even have that, said so in the chat, but that's not going to 70C, that's still set to 45-50C (70C is very hot, you'd burn yourself without mixing in cold water), but a timer for on/off doesn't apply to this.
