Several fixes.

WLAN_Thermometer.ino

@@ -3,7 +3,7 @@
 //
 // Use from 0 to 4. Higher number, more debugging messages and memory usage.
 //#define _WIFIMGR_LOGLEVEL_  4
-#define DEBUG               1
+// #define DEBUG               1
 
 #include <WiFi.h>
 #include <WiFiManager.h>
@@ -54,7 +54,7 @@ const uint8_t degree_sign[8] = { B00010, B00101, B00010, B00000, B00000, B00000,
 uint8_t add_summertime = 0;
 bool last_reset_ap_check = false;
 //bool minmax_enabled = false;
-char date_string_old[9];
+char date_string_old[11];
 char uptime_string[23];
 
 enum {
@@ -146,7 +146,7 @@ void setup()
 
   lcd.setCursor(0, 3);
   lcd.print("Getting time...");
-  DateTime.setTimeZone("CET-2");
+  DateTime.setTimeZone("CET-1");
   DateTime.setServer(NTP_SERVER);
   DateTime.begin(NTP_TIMEOUT);
   /* while (!DateTime.isTimeValid())
@@ -157,9 +157,16 @@ void setup()
   if (DateTime.isTimeValid())
   {
     if (is_wintertime(DateTime.getTime()) == false)
+    {
       add_summertime = 1;
+      DEBUG_MSG("Summertime\n");
+    }
     else
+    {
       add_summertime = 0;
+      DEBUG_MSG("Wintertime\n");
+    }
+    DEBUG_MSG("add_summertime=%d\n", add_summertime);
   }
 
   // create a degree sign
@@ -189,6 +196,9 @@ void setup()
   setup_screen();
   show_time();
   show_temperature();
+
+  DEBUG_MSG("10add_summertime=%d\n", add_summertime);
+
 }
 
 void loop()
@@ -200,12 +210,20 @@ void loop()
   if (!DateTime.isTimeValid() && millis() - 10000 > next_time_check)
   {
     next_time_check = millis();
-    DateTime.setTimeZone("CET-2");
+    DateTime.setTimeZone("CET-1");
     DateTime.forceUpdate();
+
     if (is_wintertime(DateTime.getTime()) == false)
+    {
       add_summertime = 1;
+      DEBUG_MSG("Summertime\n");
+    }
     else
+    {
       add_summertime = 0;
+      DEBUG_MSG("Wintertime\n");
+    }
+    DEBUG_MSG("add_summertime=%d\n", add_summertime);
   }
 
   WiFiClient client = server.available(); // Listen for incoming clients
@@ -410,9 +428,16 @@ void show_time(void)
     if ((p.getHours() == 2 || p.getHours() == 3) && p.getMinutes() == 0 && p.getSeconds() == 0)
     {
       if (is_wintertime(DateTime.getTime()) == false)
+      {
         add_summertime = 1;
+        DEBUG_MSG("Summertime\n");
+      }
       else
+      {
         add_summertime = 0;
+        DEBUG_MSG("Wintertime\n");
+      }
+      DEBUG_MSG("add_summertime=%d\n", add_summertime);
     }
 
     sprintf(date_string, "%02d.%02d.%4d", p.getMonthDay(), p.getMonth() + 1, p.getYear());
@@ -553,33 +578,6 @@ void get_sensor_data(void)
   else
     heat[ACT] = NAN;
 
-  /*
-    if (minmax_enabled == false && millis() > FIRST_MIN_MAX)
-    minmax_enabled = true;
-
-    if (minmax_enabled == false)
-    {
-      if (!isnan(temp[ACT]))
-      {
-        temp[MIN] = temp[ACT];
-        temp[MAX] = temp[ACT];
-      }
-
-      if (!isnan(hum[ACT]))
-      {
-        hum[MIN] = hum[ACT];
-        hum[MAX] = hum[ACT];
-      }
-
-      if (!isnan(heat[ACT]))
-      {
-        heat[MIN] = heat[ACT];
-        heat[MIN] = heat[ACT];
-      }
-    }
-    else
-    {
-  */
   if (!isnan(temp[ACT]))
   {
     if (isnan(temp[MIN]))