Most of the clocks do not have a human nearby to push the reset button (if there is one), as they're industrial automation. Alarm clocks and microwave ovens are mostly a side effect here; and yes, if you have adjusted the time manually, you'll need to do that again.
I wonder how those industrial automation clocks deal with power outages. Europe has quite reliable power, but even the best electricity providers have occasional unplanned outages.
As of a few years ago the best was Germany, where the average customer had about 15 minutes per year without power due to unplanned outages (excluding outages caused by exceptional events). (For comparison, the best quartile of utilities in the US averaged about 90 minutes/year for their average customer).
