timezone support

src/Ntp.cpp

@@ -3,16 +3,75 @@
  */
 
 #include "Ntp.h"
+#include "MyESP.h"
 
-char *    NtpClient::TimeServerName;
-time_t    NtpClient::syncInterval;
-IPAddress NtpClient::timeServer;
-AsyncUDP  NtpClient::udpListener;
-byte      NtpClient::NTPpacket[NTP_PACKET_SIZE];
+char *           NtpClient::TimeServerName;
+Timezone *       NtpClient::tz;
+TimeChangeRule * NtpClient::tcr;
+time_t           NtpClient::syncInterval;
+IPAddress        NtpClient::timeServer;
+AsyncUDP         NtpClient::udpListener;
+byte             NtpClient::NTPpacket[NTP_PACKET_SIZE];
 
-void ICACHE_FLASH_ATTR NtpClient::Ntp(const char * server, time_t syncMins) {
+// Australia Eastern Time Zone (Sydney, Melbourne)
+TimeChangeRule aEDT = {"AEDT", First, Sun, Oct, 2, 660}; // UTC + 11 hours
+TimeChangeRule aEST = {"AEST", First, Sun, Apr, 3, 600}; // UTC + 10 hours
+Timezone       ausET(aEDT, aEST);
+
+// Moscow Standard Time (MSK, does not observe DST)
+TimeChangeRule msk = {"MSK", Last, Sun, Mar, 1, 180};
+Timezone       tzMSK(msk);
+
+// Central European Time (Frankfurt, Paris)
+TimeChangeRule CEST = {"CEST", Last, Sun, Mar, 2, 120}; // Central European Summer Time
+TimeChangeRule CET  = {"CET ", Last, Sun, Oct, 3, 60};  // Central European Standard Time
+Timezone       CE(CEST, CET);
+
+// United Kingdom (London, Belfast)
+TimeChangeRule BST = {"BST", Last, Sun, Mar, 1, 60}; // British Summer Time
+TimeChangeRule GMT = {"GMT", Last, Sun, Oct, 2, 0};  // Standard Time
+Timezone       UK(BST, GMT);
+
+// UTC
+TimeChangeRule utcRule = {"UTC", Last, Sun, Mar, 1, 0}; // UTC
+Timezone       UTC(utcRule);
+
+// US Eastern Time Zone (New York, Detroit)
+TimeChangeRule usEDT = {"EDT", Second, Sun, Mar, 2, -240}; // Eastern Daylight Time = UTC - 4 hours
+TimeChangeRule usEST = {"EST", First, Sun, Nov, 2, -300};  // Eastern Standard Time = UTC - 5 hours
+Timezone       usET(usEDT, usEST);
+
+// US Central Time Zone (Chicago, Houston)
+TimeChangeRule usCDT = {"CDT", Second, Sun, Mar, 2, -300};
+TimeChangeRule usCST = {"CST", First, Sun, Nov, 2, -360};
+Timezone       usCT(usCDT, usCST);
+
+// US Mountain Time Zone (Denver, Salt Lake City)
+TimeChangeRule usMDT = {"MDT", Second, Sun, Mar, 2, -360};
+TimeChangeRule usMST = {"MST", First, Sun, Nov, 2, -420};
+Timezone       usMT(usMDT, usMST);
+
+// Arizona is US Mountain Time Zone but does not use DST
+Timezone usAZ(usMST);
+
+// US Pacific Time Zone (Las Vegas, Los Angeles)
+TimeChangeRule usPDT = {"PDT", Second, Sun, Mar, 2, -420};
+TimeChangeRule usPST = {"PST", First, Sun, Nov, 2, -480};
+Timezone       usPT(usPDT, usPST);
+
+// build index of all timezones
+Timezone * timezones[] = {&ausET, &tzMSK, &CE, &UK, &UTC, &usET, &usCT, &usMT, &usAZ, &usPT};
+
+void ICACHE_FLASH_ATTR NtpClient::Ntp(const char * server, time_t syncMins, uint8_t tz_index) {
     TimeServerName = strdup(server);
     syncInterval   = syncMins * 60; // convert to seconds
+
+    // check for out of bounds
+    if (tz_index > NTP_TIMEZONE_MAX) {
+        tz_index = NTP_TIMEZONE_DEFAULT;
+    }
+    tz = timezones[tz_index]; // set timezone
+
     WiFi.hostByName(TimeServerName, timeServer);
     setSyncProvider(getNtpTime);
     setSyncInterval(syncInterval);
@@ -35,10 +94,23 @@ time_t ICACHE_FLASH_ATTR NtpClient::getNtpTime() {
     NTPpacket[15] = 52;
     if (udpListener.connect(timeServer, 123)) {
         udpListener.onPacket([](AsyncUDPPacket packet) {
-            unsigned long highWord    = word(packet.data()[40], packet.data()[41]);
-            unsigned long lowWord     = word(packet.data()[42], packet.data()[43]);
-            time_t        UnixUTCtime = (highWord << 16 | lowWord) - 2208988800UL;
-            setTime(UnixUTCtime);
+            unsigned long highWord     = word(packet.data()[40], packet.data()[41]);
+            unsigned long lowWord      = word(packet.data()[42], packet.data()[43]);
+            time_t        UnixUTCtime  = (highWord << 16 | lowWord) - 2208988800UL;
+            time_t        adjustedtime = (*tz).toLocal(UnixUTCtime, &tcr);
+
+            myESP.myDebug("[NTP] UTC internet time is %d/%d %02d:%02d:%02d. System time set to local timezone which is %02d:%02d:%02d %s\n",
+                          to_day(UnixUTCtime),
+                          to_month(UnixUTCtime),
+                          to_hour(UnixUTCtime),
+                          to_minute(UnixUTCtime),
+                          to_second(UnixUTCtime),
+                          to_hour(adjustedtime),
+                          to_minute(adjustedtime),
+                          to_second(adjustedtime),
+                          tcr->abbrev);
+
+            setTime(adjustedtime);
         });
     }
     udpListener.write(NTPpacket, sizeof(NTPpacket));