All it took was a visit to Prague and Budapest, while they were still part of the former Soviet Block. One had the very clear sensation of being in the centre of Europe, stuck between the West (us) and the East (you know, those guys).
So, this is a solemn promise, from this day, I swear (where is my Bible ?) that I will correct anyone using this inaccurate terminology : "If you really want to experience Eastern Europe, just go to Kazan or to the Urals, then you'll understand".
BTW, your diagram showing the relation between the sidereal day and the solar day is excellent.
But the next calculation showed the Center of Europe kilometers away from the park ;-))