Tz update (#7234)

* TZ update

Added the possibility to set the timezone without using NTP. This is helpful to have the timezone advantages when using an external RTC.

* Update time.cpp

Author: kugelkopf123

cores/esp8266/Arduino.h

@@ -276,6 +276,8 @@ long secureRandom(long);
 long secureRandom(long, long);
 long map(long, long, long, long, long);
 
+void setTZ(const char* tz);
+
 void configTime(int timezone, int daylightOffset_sec, const char* server1,
     const char* server2 = nullptr, const char* server3 = nullptr);
 

cores/esp8266/time.cpp

@@ -186,17 +186,23 @@ void configTime(int timezone_sec, int daylightOffset_sec, const char* server1, c
     /*** end of posix replacement ***/
 }
 
+void setTZ(const char* tz){
+	
+    char tzram[strlen_P(tz) + 1];
+    memcpy_P(tzram, tz, sizeof(tzram));
+    setenv("TZ", tzram, 1/*overwrite*/);
+    tzset();
+}
+
 void configTime(const char* tz, const char* server1, const char* server2, const char* server3)
 {
     sntp_stop();
 
     setServer(0, server1);
     setServer(1, server2);
     setServer(2, server3);
-    char tzram[strlen_P(tz) + 1];
-    memcpy_P(tzram, tz, sizeof(tzram));
-    setenv("TZ", tzram, 1/*overwrite*/);
-    tzset();
-
+	setTZ(tz);
+	
     sntp_init();
 }
+