France, Belgium - this is NON-natural

No social measures, no natural biological processes, nor even statistic artefacts can provide so sharp change as we see in France around 7th of November. This is not natural. What is this?

See now Belgium.

The same. But happened 8 days earlier. In other European countries even in neighboring ones (like Luxembourg, Netherlands) we do not see this sharp change.

2 "miracles". What is an explanation? The problem is that we even do not try finding it. Otherwise perhaps we'll need to remove quotation marks around "miracles".