diff --git a/README.md b/README.md
index 81771f5c..1cf6607c 100644
--- a/README.md
+++ b/README.md
@@ -569,17 +569,17 @@ Send for example `83` `86` as Downlink on Port 2 to get battery status and time/
 	bytes 1..4 = time/date in UTC epoch seconds (LSB)
 	byte 5 = time source & status, see below
 	
-		bits 0..3 last seen time source
+		bits 0..3 time source
 			0x00 = GPS
 			0x01 = RTC
 			0x02 = LORA
-			0x03 = unsynched (never synched)
+			0x03 = unsynched
 			0x04 = set (source unknown)
 	
-		bits 4..7 time status
-			0x00 = timeNotSet (never synched)
-			0x01 = timeNeedsSync (last sync failed)
-			0x02 = timeSet (synched)
+		bits 4..7 esp32 sntp time status
+			0x00 = SNTP_SYNC_STATUS_RESET
+			0x01 = SNTP_SYNC_STATUS_COMPLETED
+			0x02 = SNTP_SYNC_STATUS_IN_PROGRESS
 
 0x87 sync time/date
 
diff --git a/include/dcf77.h b/include/dcf77.h
index 964389ee..df9400e9 100644
--- a/include/dcf77.h
+++ b/include/dcf77.h
@@ -4,8 +4,7 @@
 #include "globals.h"
 #include "timekeeper.h"
 
-#define DCF77_FRAME_SIZE (60)
-#define DCF77_PULSE_LENGTH (100)
+#define set_dcfbit(b) (1ULL << (b))
 
 #ifdef DCF77_ACTIVE_LOW
 enum dcf_pinstate { dcf_high, dcf_low };
@@ -13,12 +12,7 @@ enum dcf_pinstate { dcf_high, dcf_low };
 enum dcf_pinstate { dcf_low, dcf_high };
 #endif
 
-enum DCF77_Pulses { dcf_Z, dcf_0, dcf_1 };
-
-void DCF77_Pulse(time_t t, uint8_t const *DCFpulse);
-uint8_t *IRAM_ATTR DCF77_Frame(time_t const t);
-uint8_t IRAM_ATTR dec2bcd(uint8_t const dec, uint8_t const startpos, uint8_t const endpos,
-                          uint8_t *DCFpulse);
-uint8_t IRAM_ATTR setParityBit(uint8_t const p);
+void DCF77_Pulse(uint8_t bit);
+uint64_t DCF77_Frame(const struct tm t);
 
 #endif
\ No newline at end of file
diff --git a/include/globals.h b/include/globals.h
index f2547137..a3a60341 100644
--- a/include/globals.h
+++ b/include/globals.h
@@ -5,7 +5,6 @@
 #include <Arduino.h>
 
 // Time functions
-#include <ezTime.h>
 #include <RtcDateTime.h>
 #include <Ticker.h>
 
@@ -111,6 +110,7 @@ typedef struct {
   float pm25;
 } sdsStatus_t;
 
-extern char clientId[20]; // unique clientID
+extern char clientId[20];   // unique clientID
+extern time_t _COMPILETIME; // epoch build time
 
 #endif
\ No newline at end of file
diff --git a/include/gpsread.h b/include/gpsread.h
index a3cc7747..fe204bea 100644
--- a/include/gpsread.h
+++ b/include/gpsread.h
@@ -21,6 +21,5 @@ bool gps_hasfix();
 void gps_storelocation(gpsStatus_t *gps_store);
 void gps_loop(void *pvParameters);
 time_t get_gpstime(uint16_t *msec);
-time_t get_gpstime(void);
 
 #endif
\ No newline at end of file
diff --git a/include/if482.h b/include/if482.h
index c1826b8b..9a3fe92f 100644
--- a/include/if482.h
+++ b/include/if482.h
@@ -3,10 +3,11 @@
 
 #include "globals.h"
 #include "timekeeper.h"
+#include "esp_sntp.h"
 
 #define IF482_FRAME_SIZE (17)
 #define IF482_SYNC_FIXUP (10) // calibration to fixup processing time [milliseconds]
 
-String IRAM_ATTR IF482_Frame(time_t t);
+String IF482_Frame(time_t t);
 
 #endif
\ No newline at end of file
diff --git a/include/mobaserial.h b/include/mobaserial.h
deleted file mode 100644
index a9d56897..00000000
--- a/include/mobaserial.h
+++ /dev/null
@@ -1,17 +0,0 @@
-#ifndef _MOBALINE_H
-#define _MOBALINE_H
-
-#include "globals.h"
-#include "timekeeper.h"
-#include "dcf77.h"
-
-#define MOBALINE_FRAME_SIZE (33)
-#define MOBALINE_PULSE_LENGTH (100)
-#define MOBALINE_HEAD_PULSE_LENGTH (1500)
-
-void MOBALINE_Pulse(time_t t, uint8_t const *DCFpulse);
-uint8_t *IRAM_ATTR MOBALINE_Frame(time_t const t);
-void IRAM_ATTR dec2bcd(uint8_t const dec, uint8_t const startpos,
-                       uint8_t const endpos, uint8_t *DCFpulse);
-
-#endif
\ No newline at end of file
diff --git a/include/rcommand.h b/include/rcommand.h
index 75689597..0cdb23c6 100644
--- a/include/rcommand.h
+++ b/include/rcommand.h
@@ -10,6 +10,7 @@
 #include "sensor.h"
 #include "cyclic.h"
 #include "timekeeper.h"
+#include "esp_sntp.h"
 #include "timesync.h"
 #include "power.h"
 #include "antenna.h"
diff --git a/include/timekeeper.h b/include/timekeeper.h
index 2fc2c879..8eb184b4 100644
--- a/include/timekeeper.h
+++ b/include/timekeeper.h
@@ -8,6 +8,11 @@
 #include "gpsread.h"
 #include "if482.h"
 #include "dcf77.h"
+#include "esp_sntp.h"
+
+#define SECS_YR_2000  (946684800UL) // the time at the start of y2k
+#define GPS_UTC_DIFF 315964800UL // seconds diff between gps and utc epoch
+#define LEAP_SECS_SINCE_GPSEPOCH 18UL // state of 2021
 
 enum timesource_t { _gps, _rtc, _lora, _unsynced, _set };
 
@@ -15,7 +20,6 @@ extern const char timeSetSymbols[];
 extern Ticker timesyncer;
 extern timesource_t timeSource;
 extern TaskHandle_t ClockTask;
-extern Timezone myTZ;
 extern bool volatile TimePulseTick; // 1sec pps flag set by GPS or RTC
 extern hw_timer_t *ppsIRQ;
 
@@ -25,11 +29,12 @@ void clock_loop(void *pvParameters);
 void timepulse_start(void);
 void setTimeSyncIRQ(void);
 uint8_t timepulse_init(void);
-time_t timeIsValid(time_t const t);
+bool timeIsValid(time_t const t);
 void calibrateTime(void);
 void IRAM_ATTR setMyTime(uint32_t t_sec, uint16_t t_msec,
                          timesource_t mytimesource);
-time_t compiledUTC(void);
+time_t compileTime(const String compile_date);
+time_t mkgmtime(const struct tm *ptm);
 TickType_t tx_Ticks(uint32_t framesize, unsigned long baud, uint32_t config,
                     int8_t rxPin, int8_t txPins);
 
diff --git a/include/timesync.h b/include/timesync.h
index a6db2a3d..cd517421 100644
--- a/include/timesync.h
+++ b/include/timesync.h
@@ -9,8 +9,6 @@
 #define TIME_SYNC_FIXUP 25 // compensation for processing time [milliseconds]
 #define TIME_SYNC_MAX_SEQNO 0xfe // threshold for wrap around time_sync_seqNo
 #define TIME_SYNC_END_FLAG (TIME_SYNC_MAX_SEQNO + 1) // end of handshake marker
-#define GPS_UTC_DIFF 315964800UL // seconds diff between gps and utc epoch
-#define LEAP_SECS_SINCE_GPSEPOCH 18UL // state of 2021
 
 enum timesync_t {
   timesync_tx,
diff --git a/platformio_orig.ini b/platformio_orig.ini
index c0868236..100ede8a 100644
--- a/platformio_orig.ini
+++ b/platformio_orig.ini
@@ -48,7 +48,7 @@ description = Paxcounter is a device for metering passenger flows in realtime. I
 
 [common]
 ; for release_version use max. 10 chars total, use any decimal format like "a.b.c"
-release_version = 3.0.3
+release_version = 3.1.0
 ; DEBUG LEVEL: For production run set to 0, otherwise device will leak RAM while running!
 ; 0=None, 1=Error, 2=Warn, 3=Info, 4=Debug, 5=Verbose
 debug_level = 3
@@ -82,7 +82,6 @@ lib_deps_basic =
     https://github.com/dbSuS/libpax.git @ ^1.0.0
     https://github.com/SukkoPera/Arduino-Rokkit-Hash.git
     bblanchon/ArduinoJson @ ^6
-    ropg/ezTime @ ^0.8.3
     makuna/RTC @ ^2.3.5
     spacehuhn/SimpleButton 
     lewisxhe/AXP202X_Library @ ^1.1.3
diff --git a/src/dcf77.cpp b/src/dcf77.cpp
index e579b216..fd59cb51 100644
--- a/src/dcf77.cpp
+++ b/src/dcf77.cpp
@@ -17,104 +17,96 @@ https://github.com/udoklein/dcf77
 static const char TAG[] = __FILE__;
 
 // triggered by second timepulse to ticker out DCF signal
-void DCF77_Pulse(time_t t, uint8_t const *DCFpulse) {
+void DCF77_Pulse(uint8_t bit) {
 
-  TickType_t startTime = xTaskGetTickCount();
-  uint8_t sec = myTZ.second(t);
-
-  ESP_LOGD(TAG, "[%s] DCF second: %d", myTZ.dateTime("H:i:s.v").c_str(), sec);
+  TickType_t startTime;
 
   // induce a DCF Pulse
-  for (uint8_t pulse = 0; pulse <= 2; pulse++) {
+  for (uint8_t pulseLength = 0; pulseLength <= 2; pulseLength++) {
 
-    switch (pulse) {
+    startTime = xTaskGetTickCount(); // reference time pulse start
 
-    case 0: // start of second -> start of timeframe for logic signal
-      if (DCFpulse[sec] != dcf_Z)
-        digitalWrite(HAS_DCF77, dcf_low);
+    switch (pulseLength) {
+
+    case 0: // 0ms = start of pulse
+      digitalWrite(HAS_DCF77, dcf_low);
       break;
 
-    case 1: // 100ms after start of second -> end of timeframe for logic 0
-      if (DCFpulse[sec] == dcf_0)
+    case 1: // 100ms = logic 0
+      if (bit == 0)
         digitalWrite(HAS_DCF77, dcf_high);
       break;
 
-    case 2: // 200ms after start of second -> end of timeframe for logic 1
+    case 2: // 200ms = logic 1
       digitalWrite(HAS_DCF77, dcf_high);
       break;
 
     } // switch
 
-    // pulse pause
-    vTaskDelayUntil(&startTime, pdMS_TO_TICKS(DCF77_PULSE_LENGTH));
+    // delay to genrate pulseLength
+    vTaskDelayUntil(&startTime, pdMS_TO_TICKS(100));
 
   } // for
 } // DCF77_Pulse()
 
-uint8_t *IRAM_ATTR DCF77_Frame(time_t const t) {
+// helper function to convert decimal to bcd digit
+uint64_t dec2bcd(uint8_t const dec, uint8_t const startpos,
+                 uint8_t const endpos, uint8_t *odd_parity) {
 
-  // array of dcf pulses for one minute, secs 0..16 and 20 are never touched, so
-  // we keep them statically to avoid same recalculation every minute
+  uint8_t data = (dec < 10) ? dec : ((dec / 10) << 4) + (dec % 10);
+  uint64_t bcd = 0;
 
-  static uint8_t DCFpulse[DCF77_FRAME_SIZE + 1] = {
-      dcf_0, dcf_0, dcf_0, dcf_0, dcf_0, dcf_0, dcf_0,
-      dcf_0, dcf_0, dcf_0, dcf_0, dcf_0, dcf_0, dcf_0,
-      dcf_0, dcf_0, dcf_0, dcf_0, dcf_0, dcf_0, dcf_1};
+  *odd_parity = 0;
+  for (uint8_t i = startpos; i <= endpos; i++) {
+    bcd += (data & 1) ? set_dcfbit(i) : 0;
+    *odd_parity += (data & 1);
+    data >>= 1;
+  }
+  *odd_parity %= 2;
 
-  uint8_t Parity;
+  return bcd;
+}
 
-  // ENCODE DST CHANGE ANNOUNCEMENT (Sec 16)
-  DCFpulse[16] = dcf_0; // not yet implemented
+// generates a 1 minute dcf pulse frame for calendar time t
+uint64_t DCF77_Frame(const struct tm t) {
 
-  // ENCODE DAYLIGHTSAVING (secs 17..18)
-  DCFpulse[17] = myTZ.isDST(t) ? dcf_1 : dcf_0;
-  DCFpulse[18] = myTZ.isDST(t) ? dcf_0 : dcf_1;
+  uint8_t parity = 0, parity_sum = 0;
+  uint64_t frame = 0; // start with all bits 0
 
-  // ENCODE MINUTE (secs 21..28)
-  Parity = dec2bcd(myTZ.minute(t), 21, 27, DCFpulse);
-  DCFpulse[28] = setParityBit(Parity);
+  // DST CHANGE ANNOUNCEMENT (16)
+  // -- not implemented --
 
-  // ENCODE HOUR (secs 29..35)
-  Parity = dec2bcd(myTZ.hour(t), 29, 34, DCFpulse);
-  DCFpulse[35] = setParityBit(Parity);
+  // DAYLIGHTSAVING  (17, 18)
+  // "01" = MEZ / "10" = MESZ
+  frame += t.tm_isdst > 0 ? set_dcfbit(17) : set_dcfbit(18);
 
-  // ENCODE DATE (secs 36..58)
-  Parity = dec2bcd(myTZ.day(t), 36, 41, DCFpulse);
-  Parity += dec2bcd((myTZ.weekday(t) - 1) ? (myTZ.weekday(t) - 1) : 7, 42, 44,
-                    DCFpulse);
-  Parity += dec2bcd(myTZ.month(t), 45, 49, DCFpulse);
-  Parity += dec2bcd(myTZ.year(t) - 2000, 50, 57, DCFpulse);
-  DCFpulse[58] = setParityBit(Parity);
+  // LEAP SECOND (19)
+  // -- not implemented --
 
-  // ENCODE MARK (sec 59)
-  DCFpulse[59] = dcf_Z; // !! missing code here for leap second !!
+  // BEGIN OF TIME INFORMATION (20)
+  frame += set_dcfbit(20);
 
-  // timestamp this frame with it's minute
-  DCFpulse[60] = myTZ.minute(t);
+  // MINUTE (21..28)
+  frame += dec2bcd(t.tm_min, 21, 27, &parity);
+  frame += parity ? set_dcfbit(28) : 0;
 
-  return DCFpulse;
+  // HOUR (29..35)
+  frame += dec2bcd(t.tm_hour, 29, 34, &parity);
+  frame += parity ? set_dcfbit(35) : 0;
+
+  // DATE (36..58)
+  frame += dec2bcd(t.tm_mday, 36, 41, &parity);
+  parity_sum += parity;
+  frame += dec2bcd((t.tm_wday == 0) ? 7 : t.tm_wday, 42, 44, &parity);
+  parity_sum += parity;
+  frame += dec2bcd(t.tm_mon + 1, 45, 49, &parity);
+  parity_sum += parity;
+  frame += dec2bcd(t.tm_year + 1900 - 2000, 50, 57, &parity);
+  parity_sum += parity;
+  frame += parity_sum % 2 ? set_dcfbit(58) : 0;
+
+  return frame;
 
 } // DCF77_Frame()
 
-// helper function to convert decimal to bcd digit
-uint8_t IRAM_ATTR dec2bcd(uint8_t const dec, uint8_t const startpos,
-                          uint8_t const endpos, uint8_t *DCFpulse) {
-
-  uint8_t data = (dec < 10) ? dec : ((dec / 10) << 4) + (dec % 10);
-  uint8_t parity = 0;
-
-  for (uint8_t i = startpos; i <= endpos; i++) {
-    DCFpulse[i] = (data & 1) ? dcf_1 : dcf_0;
-    parity += (data & 1);
-    data >>= 1;
-  }
-
-  return parity;
-}
-
-// helper function to encode parity
-uint8_t IRAM_ATTR setParityBit(uint8_t const p) {
-  return ((p & 1) ? dcf_1 : dcf_0);
-}
-
 #endif // HAS_DCF77
\ No newline at end of file
diff --git a/src/display.cpp b/src/display.cpp
index 34046274..fdf70904 100644
--- a/src/display.cpp
+++ b/src/display.cpp
@@ -220,7 +220,10 @@ void dp_drawPage(bool nextpage) {
   // nextpage = true -> flip 1 page
 
   static uint8_t DisplayPage = 0;
-  char timeState;
+  char timeState, strftime_buf[64];
+  time_t now;
+  struct tm timeinfo = {0};
+
 #if (HAS_GPS)
   static bool wasnofix = true;
 #endif
@@ -320,11 +323,15 @@ void dp_drawPage(bool nextpage) {
     dp_println();
 
     // line 6: time + date
-    // 27.Feb 2019 20:27:00*
+    // Wed Jan 12 21:49:08 *
+
 #if (TIME_SYNC_INTERVAL)
     timeState = TimePulseTick ? ' ' : timeSetSymbols[timeSource];
     TimePulseTick = false;
-    dp_printf("%s", myTZ.dateTime("d.M Y H:i:s").c_str());
+    time(&now);
+    localtime_r(&now, &timeinfo);
+    strftime(strftime_buf, sizeof(strftime_buf), "%c", &timeinfo);
+    dp_printf("%.20s", strftime_buf);
 
 // display inverse timeState if clock controller is enabled
 #if (defined HAS_DCF77) || (defined HAS_IF482)
@@ -442,7 +449,10 @@ void dp_drawPage(bool nextpage) {
 
     dp_setFont(MY_FONT_LARGE);
     dp_setTextCursor(0, 4);
-    dp_printf("%s", myTZ.dateTime("H:i:s").c_str());
+    time(&now);
+    localtime_r(&now, &timeinfo);
+    strftime(strftime_buf, sizeof(strftime_buf), "%T", &timeinfo);
+    dp_printf("%.8s", strftime_buf);
     break;
 
   // ---------- page 5: pax graph ----------
diff --git a/src/gpsread.cpp b/src/gpsread.cpp
index ab163a24..428604e4 100644
--- a/src/gpsread.cpp
+++ b/src/gpsread.cpp
@@ -89,7 +89,7 @@ bool gps_hasfix() {
           gps.altitude.age() < 4000);
 }
 
-// function to poll current time from GPS data; note: this is costly
+// function to poll UTC time from GPS NMEA data; note: this is costly
 time_t get_gpstime(uint16_t *msec) {
 
   // poll NMEA ZDA sentence
@@ -104,27 +104,26 @@ time_t get_gpstime(uint16_t *msec) {
   // did we get a current date & time?
   if (gpstime.isValid()) {
 
-    time_t t = 0;
-    tmElements_t tm;
     uint32_t delay_ms =
         gpstime.age() + nmea_txDelay_ms + NMEA_COMPENSATION_FACTOR;
     uint32_t zdatime = atof(gpstime.value());
 
-    // convert time to maketime format and make time
-    tm.Second = zdatime % 100;              // second
-    tm.Minute = (zdatime / 100) % 100;      // minute
-    tm.Hour = zdatime / 10000;              // hour
-    tm.Day = atoi(gpsday.value());          // day
-    tm.Month = atoi(gpsmonth.value());      // month
-    tm.Year = atoi(gpsyear.value()) - 1970; // year offset from 1970
-    t = makeTime(tm);
-
-    ESP_LOGD(TAG, "GPS date/time: %s",
-             UTC.dateTime(t, "d.M Y H:i:s.v T").c_str());
+    // convert UTC time from gps NMEA ZDA sentence to tm format
+    struct tm gps_tm = {0};
+    gps_tm.tm_sec = zdatime % 100;                 // second (UTC)
+    gps_tm.tm_min = (zdatime / 100) % 100;         // minute (UTC)
+    gps_tm.tm_hour = zdatime / 10000;              // hour (UTC)
+    gps_tm.tm_mday = atoi(gpsday.value());         // day, 01 to 31
+    gps_tm.tm_mon = atoi(gpsmonth.value()) - 1;    // month, 01 to 12
+    gps_tm.tm_year = atoi(gpsyear.value()) - 1900; // year, YYYY
+    
+    // convert UTC tm to time_t epoch
+    gps_tm.tm_isdst = 0; // UTC has no DST 
+    time_t t = mkgmtime(&gps_tm);
 
     // add protocol delay with millisecond precision
-    t += delay_ms / 1000 - 1; // whole seconds
-    *msec = delay_ms % 1000;  // fractional seconds
+    t += (time_t)(delay_ms / 1000);
+    *msec = delay_ms % 1000; // fractional seconds
 
     return t;
   }
@@ -135,11 +134,6 @@ time_t get_gpstime(uint16_t *msec) {
 
 } // get_gpstime()
 
-time_t get_gpstime(void) {
-  uint16_t msec;
-  return get_gpstime(&msec);
-}
-
 // GPS serial feed FreeRTos Task
 void gps_loop(void *pvParameters) {
 
@@ -152,12 +146,14 @@ void gps_loop(void *pvParameters) {
       // feed GPS decoder with serial NMEA data from GPS device
       while (GPS_Serial.available()) {
         gps.encode(GPS_Serial.read());
+        yield();
       }
 #elif defined GPS_I2C
       Wire.requestFrom(GPS_ADDR, 32); // caution: this is a blocking call
       while (Wire.available()) {
         gps.encode(Wire.read());
         delay(2); // 2ms delay according L76 datasheet
+        yield();
       }
 #endif
 
@@ -165,18 +161,18 @@ void gps_loop(void *pvParameters) {
       // GPS time, we trigger a device time update to poll time from GPS
       if ((timeSource == _unsynced || timeSource == _set) &&
           (gpstime.isUpdated() && gpstime.isValid() && gpstime.age() < 1000)) {
-        now();
         calibrateTime();
       }
 
     } // if
 
-    // show NMEA data in verbose mode, useful only for debugging GPS, very noisy
-    // ESP_LOGV(TAG, "GPS NMEA data: passed %u / failed: %u / with fix: %u",
+    // show NMEA data in verbose mode, useful only for debugging GPS, very
+    // noisy ESP_LOGV(TAG, "GPS NMEA data: passed %u / failed: %u / with fix:
+    // %u",
     //         gps.passedChecksum(), gps.failedChecksum(),
     //         gps.sentencesWithFix());
 
-    delay(2); // yield to CPU
+    yield(); // yield to CPU
 
   } // end of infinite loop
 
diff --git a/src/if482.cpp b/src/if482.cpp
index afbc16cc..37c12c38 100644
--- a/src/if482.cpp
+++ b/src/if482.cpp
@@ -84,27 +84,20 @@ not evaluated by model BU-190, use "F" instead for this model
 // Local logging tag
 static const char TAG[] = __FILE__;
 
-String IRAM_ATTR IF482_Frame(time_t t) {
+String IF482_Frame(time_t t) {
 
   char mon, out[IF482_FRAME_SIZE + 1];
 
-  switch (timeStatus()) { // indicates if time has been set and recently synced
-  case timeSet:           // time is set and is synced
-    mon = 'A';
-    break;
-  case timeNeedsSync: // time had been set but sync attempt did not succeed
-    mon = 'M';
-    break;
-  default: // unknown time status (should never be reached)
-    mon = '?';
-    break;
-  } // switch
+  if (sntp_get_sync_status() == SNTP_SYNC_STATUS_IN_PROGRESS)
+    mon = 'M'; // time had been set but sync not completed
+  else
+    mon = 'A'; // time has been set and was recently synced
 
   // generate IF482 telegram
-  snprintf(out, sizeof(out), "O%cL%s\r", mon, myTZ.dateTime(t, UTC_TIME, "ymdwHis").c_str());
+  // snprintf(out, sizeof(out), "O%cL%s\r", mon, myTZ.dateTime(t, UTC_TIME,
+  // "ymdwHis").c_str());
 
-  ESP_LOGD(TAG, "[%s] IF482 date/time: %s", myTZ.dateTime("H:i:s.v").c_str(),
-           out);
+  // ESP_LOGD(TAG, "[%s] IF482 date/time: %s", ctime(time(NULL), out);
 
   return out;
 }
diff --git a/src/irqhandler.cpp b/src/irqhandler.cpp
index f6a6e295..b971aeac 100644
--- a/src/irqhandler.cpp
+++ b/src/irqhandler.cpp
@@ -51,7 +51,6 @@ void irqHandler(void *pvParameters) {
 #if (TIME_SYNC_INTERVAL)
     // is time to be synced?
     if (irqSource & TIMESYNC_IRQ) {
-      now(); // ensure sysTime is recent
       calibrateTime();
     }
 #endif
diff --git a/src/ledmatrixdisplay.cpp b/src/ledmatrixdisplay.cpp
index 2abd38aa..e6b1d070 100644
--- a/src/ledmatrixdisplay.cpp
+++ b/src/ledmatrixdisplay.cpp
@@ -12,7 +12,7 @@ static const char TAG[] = __FILE__;
 uint8_t MatrixDisplayIsOn = 0;
 static uint8_t displaybuf[LED_MATRIX_WIDTH * LED_MATRIX_HEIGHT / 8] = {0};
 static unsigned long ulLastNumMacs = 0;
-static time_t ulLastTime = now();
+static time_t ulLastTime = time(NULL);
 
 hw_timer_t *matrixDisplayIRQ = NULL;
 
@@ -116,11 +116,11 @@ void refreshTheMatrixDisplay(bool nextPage) {
 
   case 1:
 
-    const time_t t = now();
+    const time_t t = time(NULL);
     if (ulLastTime != t) {
       ulLastTime = t;
       matrix.clear();
-      DrawNumber(myTZ.dateTime("H:i:s").c_str());
+      //DrawNumber(myTZ.dateTime("H:i:s").c_str());
     }
     break;
 
diff --git a/src/main.cpp b/src/main.cpp
index 82587c23..fda59d8e 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -126,6 +126,7 @@ void setup() {
   snprintf(clientId, 20, "paxcounter_%08x", hashedmac);
   ESP_LOGI(TAG, "Starting %s v%s (runmode=%d / restarts=%d)", clientId,
            PROGVERSION, RTC_runmode, RTC_restarts);
+  ESP_LOGI(TAG, "code build date: %d", _COMPILETIME);
 
   // print chip information on startup if in verbose mode after coldstart
 #if (VERBOSE)
@@ -448,7 +449,7 @@ void setup() {
     ESP_LOGI(TAG, "BME sensor initialized");
   else {
     ESP_LOGE(TAG, "BME sensor could not be initialized");
-    cfg.payloadmask &= ~MEMS_DATA; // switch off transmit of BME data
+    cfg.payloadmask &= (uint8_t)~MEMS_DATA; // switch off transmit of BME data
   }
 #endif
 
diff --git a/src/mobaserial.cpp b/src/mobaserial.cpp
deleted file mode 100644
index bffdea09..00000000
--- a/src/mobaserial.cpp
+++ /dev/null
@@ -1,108 +0,0 @@
-/*
-// Emulate a MOBATIME serial clock controller
-//
-// Protocol published and described here:
-//
-//
-http://www.elektrorevue.cz/cz/download/time-distribution-within-industry-4-0-platform--controlling-slave-clocks-via-master-clock-hn50/
-*/
-
-#ifdef HAS_MOBALINE
-
-#include "mobaline.h"
-
-// Local logging tag
-static const char TAG[] = __FILE__;
-
-// triggered by pulse per second to ticker out mobaline frame
-void MOBALINE_Pulse(time_t t, uint8_t const *DCFpulse) {
-
-  TickType_t startTime = xTaskGetTickCount();
-  uint8_t sec = myTZ.second(t);
-
-  ESP_LOGD(TAG, "[%s] MOBALINE sec: %d", myTZ.dateTime("H:i:s.v").c_str(),
-           sec);
-
-  // induce 3 pulses
-  for (uint8_t pulse = 0; pulse <= 3; pulse++) {
-
-    switch (pulse) {
-
-    case 0: // start of bit -> start of timeframe for logic signal
-      if (DCFpulse[sec] != dcf_Z) {
-        digitalWrite(HAS_DCF77, dcf_high);
-        vTaskDelay(pdMS_TO_TICKS(MOBALINE_HEAD_PULSE_LENGTH));
-        digitalWrite(HAS_DCF77, dcf_high);
-        vTaskDelay(pdMS_TO_TICKS(MOBALINE_HEAD_PULSE_LENGTH));
-        return; // next bit
-      } else    // start the signalling for the next bit
-        digitalWrite(HAS_DCF77, dcf_high);
-      break;
-
-    case 1: // 100ms after start of bit -> end of timeframe for logic 0
-      if (DCFpulse[sec] == dcf_1)
-        digitalWrite(HAS_DCF77, dcf_low);
-      break;
-
-    case 2: // 200ms after start of bit -> end of timeframe for logic 1
-      if (DCFpulse[sec] == dcf_0)
-        digitalWrite(HAS_DCF77, dcf_low);
-      break;
-
-    case 3: // 300ms after start -> last pulse
-      break;
-
-    } // switch
-
-    // pulse pause
-    vTaskDelayUntil(&startTime, pdMS_TO_TICKS(MOBALINE_PULSE_LENGTH));
-
-  } // for
-} // DCF77_Pulse()
-
-uint8_t *IRAM_ATTR MOBALINE_Frame(time_t const tt) {
-
-  // array of dcf pulses for one minute, secs 0..16 and 20 are never touched, so
-  // we keep them statically to avoid same recalculation every minute
-
-  static uint8_t DCFpulse[DCF77_FRAME_SIZE + 1];
-
-  time_t t = myTZ.tzTime(tt); // convert to local time
-
-  // ENCODE HEAD (bit 0))
-  DCFpulse[0] = dcf_Z; // not yet implemented
-
-  // ENCODE DAYLIGHTSAVING (bit 1)
-  DCFpulse[1] = myTZ.isDST(t) ? dcf_1 : dcf_0;
-
-  // ENCODE DATE (bits 2..20)
-  dec2bcd(false, year(t) - 2000, 2, 9, DCFpulse);
-  dec2bcd(false, month(t), 10, 14, DCFpulse);
-  dec2bcd(false, day(t), 15, 20, DCFpulse);
-
-  // ENCODE HOUR (bits 21..26)
-  dec2bcd2(false, hour(t), 21, 26, DCFpulse);
-
-  // ENCODE MINUTE (bits 27..33)
-  dec2bcd2(false, minute(t), 27, 33, DCFpulse);
-
-  // timestamp this frame with it's minute
-  DCFpulse[34] = minute(t);
-
-  return DCFpulse;
-
-} // MOBALINE_Frame()
-
-// helper function to convert decimal to bcd digit msb
-void IRAM_ATTR dec2bcd(uint8_t const dec, uint8_t const startpos,
-                       uint8_t const endpos, uint8_t *DCFpulse) {
-
-  uint8_t data = (dec < 10) ? dec : ((dec / 10) << 4) + (dec % 10);
-
-  for (uint8_t i = endpos; i >= startpos; i--) {
-    DCFpulse[i] = (data & 1) ? dcf_1 : dcf_0;
-    data >>= 1;
-  }
-}
-
-#endif // HAS_MOBALINE
\ No newline at end of file
diff --git a/src/rcommand.cpp b/src/rcommand.cpp
index 2f747958..08c7618d 100644
--- a/src/rcommand.cpp
+++ b/src/rcommand.cpp
@@ -372,10 +372,10 @@ void get_batt(uint8_t val[]) {
 
 void get_time(uint8_t val[]) {
   ESP_LOGI(TAG, "Remote command: get time");
-  time_t t = now();
+  time_t t = time(NULL);
   payload.reset();
   payload.addTime(t);
-  payload.addByte(timeStatus() << 4 | timeSource);
+  payload.addByte(sntp_get_sync_status() << 4 | timeSource);
   SendPayload(TIMEPORT);
 };
 
@@ -401,9 +401,9 @@ void set_enscount(uint8_t val[]) {
   ESP_LOGI(TAG, "Remote command: set ENS_COUNT to %s", val[0] ? "on" : "off");
   cfg.enscount = val[0] ? 1 : 0;
   if (val[0])
-    cfg.payloadmask |= SENSOR1_DATA;
+    cfg.payloadmask |= (uint8_t)SENSOR1_DATA;
   else
-    cfg.payloadmask &= ~SENSOR1_DATA;
+    cfg.payloadmask &= (uint8_t)~SENSOR1_DATA;
 }
 
 void set_loadconfig(uint8_t val[]) {
diff --git a/src/reset.cpp b/src/reset.cpp
index 7827b80a..d21a042d 100644
--- a/src/reset.cpp
+++ b/src/reset.cpp
@@ -15,7 +15,6 @@ RTC_NOINIT_ATTR uint32_t RTC_restarts;
 // RTC_DATA_ATTR -> keep values after a wakeup from sleep
 RTC_DATA_ATTR struct timeval RTC_sleep_start_time;
 RTC_DATA_ATTR unsigned long long RTC_millis = 0;
-RTC_DATA_ATTR time_t RTC_time = 0;
 
 timeval sleep_stop_time;
 
@@ -49,8 +48,9 @@ void do_after_reset(void) {
 
   // set time zone to user value from paxcounter.conf
 #ifdef TIME_SYNC_TIMEZONE
-  myTZ.setPosix(TIME_SYNC_TIMEZONE);
-  ESP_LOGD(TAG, "Timezone set to %s", myTZ.getPosix().c_str());
+  setenv("TZ", TIME_SYNC_TIMEZONE, 1);
+  tzset();
+  ESP_LOGD(TAG, "Timezone set to %s", TIME_SYNC_TIMEZONE);
 #endif
 
   switch (rtc_get_reset_reason(0)) {
@@ -75,8 +75,8 @@ void do_after_reset(void) {
     RTC_millis += sleep_time_ms; // increment system monotonic time
     ESP_LOGI(TAG, "Time spent in deep sleep: %d ms", sleep_time_ms);
 
-    // restore time
-    setMyTime(RTC_time, sleep_time_ms, _set);
+    // do we have a valid time? -> set global variable
+    timeSource = timeIsValid(sleep_stop_time.tv_sec) ? _set : _unsynced;
 
     // set wakeup state, not if we have pending OTA update
     if (RTC_runmode == RUNMODE_SLEEP)
@@ -196,7 +196,6 @@ void enter_deepsleep(const uint64_t wakeup_sec, gpio_num_t wakeup_gpio) {
   // time stamp sleep start time and save system monotonic time. Deep sleep.
   gettimeofday(&RTC_sleep_start_time, NULL);
   RTC_millis += millis();
-  RTC_time = now();
   ESP_LOGI(TAG, "Going to sleep, good bye.");
   esp_deep_sleep_start();
 }
diff --git a/src/sdcard.cpp b/src/sdcard.cpp
index 197edcfd..925ab207 100644
--- a/src/sdcard.cpp
+++ b/src/sdcard.cpp
@@ -43,7 +43,11 @@ void sdcardWriteData(uint16_t noWifi, uint16_t noBle,
                      __attribute__((unused)) uint16_t noBleCWA) {
   static int counterWrites = 0;
   char tempBuffer[12 + 1];
-  time_t t = now();
+  time_t t = time(NULL);
+  struct tm tt;
+  localtime_r(&t, &tt);
+  mktime(&tt);
+
 #if (HAS_SDS011)
   sdsStatus_t sds;
 #endif
@@ -52,9 +56,9 @@ void sdcardWriteData(uint16_t noWifi, uint16_t noBle,
     return;
 
   ESP_LOGD(TAG, "writing to SD-card");
-  sprintf(tempBuffer, "%02d.%02d.%4d,", day(t), month(t), year(t));
+  strftime(tempBuffer, sizeof(tempBuffer), "%d.%m.%Y", &tt);
   fileSDCard.print(tempBuffer);
-  sprintf(tempBuffer, "%02d:%02d:%02d,", hour(t), minute(t), second(t));
+  strftime(tempBuffer, sizeof(tempBuffer), "%H.%M.%S", &tt);
   fileSDCard.print(tempBuffer);
   sprintf(tempBuffer, "%d,%d", noWifi, noBle);
   fileSDCard.print(tempBuffer);
diff --git a/src/timekeeper.cpp b/src/timekeeper.cpp
index b1512bb8..876bff85 100644
--- a/src/timekeeper.cpp
+++ b/src/timekeeper.cpp
@@ -8,37 +8,39 @@
 #endif
 #endif
 
-#define _COMPILETIME compileTime()
+#if (defined HAS_DCF77 && defined HAS_IF482)
+#error You must define at most one of IF482 or DCF77!
+#endif
 
 // Local logging tag
 static const char TAG[] = __FILE__;
 
 // symbol to display current time source
-// G = GPS / R = RTC / L = LORA / ? = unsynced / <blank> = sync unknown
-const char timeSetSymbols[] = {'G', 'R', 'L', '?', ' '};
-
-// set Time Zone
-Timezone myTZ;
+// G = GPS / R = RTC / L = LORA / * = no sync / ? = never synced
+const char timeSetSymbols[] = {'G', 'R', 'L', '*', '?'};
 
 bool volatile TimePulseTick = false;
 timesource_t timeSource = _unsynced;
-
+time_t _COMPILETIME = compileTime(__DATE__);
 TaskHandle_t ClockTask = NULL;
 hw_timer_t *ppsIRQ = NULL;
 
 #ifdef HAS_IF482
+HardwareSerial IF482(2); // use UART #2 (#1 may be in use for serial GPS)
+static TickType_t txDelay = pdMS_TO_TICKS(1000 - IF482_SYNC_FIXUP) -
+                            tx_Ticks(IF482_FRAME_SIZE, HAS_IF482);
 #if (HAS_SDS011)
 #error cannot use IF482 together with SDS011 (both use UART#2)
 #endif
-HardwareSerial IF482(2); // use UART #2 (#1 may be in use for serial GPS)
-#endif
+
+#endif // HAS_IF482
 
 Ticker timesyncer;
 
 void setTimeSyncIRQ() { xTaskNotify(irqHandlerTask, TIMESYNC_IRQ, eSetBits); }
 
 void calibrateTime(void) {
-  ESP_LOGD(TAG, "[%0.3f] calibrateTime, timeSource == %d", millis() / 1000.0,
+  ESP_LOGD(TAG, "[%0.3f] calibrateTime, timeSource == %d", _seconds(),
            timeSource);
   time_t t = 0;
   uint16_t t_msec = 0;
@@ -76,15 +78,17 @@ void calibrateTime(void) {
 
 } // calibrateTime()
 
-// adjust system time, calibrate RTC and RTC_INT pps
+// set system time (UTC), calibrate RTC and RTC_INT pps
 void IRAM_ATTR setMyTime(uint32_t t_sec, uint16_t t_msec,
                          timesource_t mytimesource) {
 
+  struct timeval tv = {0};
+
   // called with invalid timesource?
   if (mytimesource == _unsynced)
     return;
 
-  // increment t_sec only if t_msec > 1000
+  // increment t_sec if t_msec > 1000
   time_t time_to_set = (time_t)(t_sec + t_msec / 1000);
 
   // do we have a valid time?
@@ -97,8 +101,18 @@ void IRAM_ATTR setMyTime(uint32_t t_sec, uint16_t t_msec,
       vTaskDelay(pdMS_TO_TICKS(1000 - t_msec % 1000));
     }
 
-    ESP_LOGI(TAG, "[%0.3f] UTC time: %d.%03d sec", _seconds(), time_to_set,
-             t_msec % 1000);
+    tv.tv_sec = time_to_set;
+    tv.tv_usec = 0;
+    sntp_sync_time(&tv);
+
+    ESP_LOGI(TAG, "[%0.3f] UTC time: %d.000 sec", _seconds(), time_to_set);
+
+    // if we have a software pps timer, shift it to top of second
+    if (ppsIRQ != NULL) {
+
+      timerWrite(ppsIRQ, 0); // reset pps timer
+      CLOCKIRQ();            // fire clock pps, this advances time 1 sec
+    }
 
 // if we have got an external timesource, set RTC time and shift RTC_INT pulse
 // to top of second
@@ -107,15 +121,8 @@ void IRAM_ATTR setMyTime(uint32_t t_sec, uint16_t t_msec,
       set_rtctime(time_to_set);
 #endif
 
-    // if we have a software pps timer, shift it to top of second
-    if (ppsIRQ != NULL) {
-      timerWrite(ppsIRQ, 0); // reset pps timer
-      CLOCKIRQ();            // fire clock pps, this advances time 1 sec
-    }
-
-    UTC.setTime(time_to_set); // set the time on top of second
-
     timeSource = mytimesource; // set global variable
+
     timesyncer.attach(TIME_SYNC_INTERVAL * 60, setTimeSyncIRQ);
     ESP_LOGD(TAG, "[%0.3f] Timesync finished, time was set | timesource=%d",
              _seconds(), mytimesource);
@@ -132,6 +139,10 @@ void IRAM_ATTR setMyTime(uint32_t t_sec, uint16_t t_msec,
 // helper function to setup a pulse per second for time synchronisation
 uint8_t timepulse_init() {
 
+  // set esp-idf API sntp sync mode
+  //sntp_init();
+  sntp_set_sync_mode(SNTP_SYNC_MODE_IMMED);
+
 // use time pulse from GPS as time base with fixed 1Hz frequency
 #ifdef GPS_INT
 
@@ -192,11 +203,9 @@ void IRAM_ATTR CLOCKIRQ(void) {
 
   BaseType_t xHigherPriorityTaskWoken = pdFALSE;
 
-  // syncToPPS(); // currently not used
-
 // advance wall clock, if we have
 #if (defined HAS_IF482 || defined HAS_DCF77)
-  xTaskNotifyFromISR(ClockTask, uint32_t(now()), eSetBits,
+  xTaskNotifyFromISR(ClockTask, uint32_t(time(NULL)), eSetBits,
                      &xHigherPriorityTaskWoken);
 #endif
 
@@ -213,9 +222,9 @@ void IRAM_ATTR CLOCKIRQ(void) {
 }
 
 // helper function to check plausibility of a given epoch time
-time_t timeIsValid(time_t const t) {
-  // is it a time in the past? we use compile date to guess
-  return (t < myTZ.tzTime(_COMPILETIME) ? 0 : t);
+bool timeIsValid(time_t const t) {
+  // is t a time in the past? we use compile time to guess
+  return (t > _COMPILETIME);
 }
 
 // helper function to calculate serial transmit time
@@ -230,12 +239,6 @@ TickType_t tx_Ticks(uint32_t framesize, unsigned long baud, uint32_t config,
   return round(txTime);
 }
 
-#if (defined HAS_IF482 || defined HAS_DCF77)
-
-#if (defined HAS_DCF77 && defined HAS_IF482)
-#error You must define at most one of IF482 or DCF77!
-#endif
-
 void clock_init(void) {
 
 // setup clock output interface
@@ -245,73 +248,80 @@ void clock_init(void) {
   pinMode(HAS_DCF77, OUTPUT);
 #endif
 
-  time_t userUTCTime = now();
-
-  xTaskCreatePinnedToCore(clock_loop,           // task function
-                          "clockloop",          // name of task
-                          2048,                 // stack size of task
-                          (void *)&userUTCTime, // start time as task parameter
-                          4,                    // priority of the task
-                          &ClockTask,           // task handle
-                          1);                   // CPU core
+  xTaskCreatePinnedToCore(clock_loop,  // task function
+                          "clockloop", // name of task
+                          3072,        // stack size of task
+                          (void *)1,   // task parameter
+                          4,           // priority of the task
+                          &ClockTask,  // task handle
+                          1);          // CPU core
 
   _ASSERT(ClockTask != NULL); // has clock task started?
 } // clock_init
 
 void clock_loop(void *taskparameter) { // ClockTask
 
-  // caveat: don't use now() in this task, it will cause a race condition
-  // due to concurrent access to i2c bus when reading/writing from/to rtc chip!
-
-#define nextmin(t) (t + DCF77_FRAME_SIZE + 1) // next minute
-
+  uint64_t ClockPulse = 0;
+  uint32_t current_time = 0, previous_time = 0;
+  int8_t ClockMinute = -1;
+  time_t tt;
+  struct tm t = {0};
 #ifdef HAS_TWO_LED
   static bool led1_state = false;
 #endif
-  uint32_t printtime;
-  time_t t = *((time_t *)taskparameter), last_printtime = 0; // UTC time seconds
-
-#ifdef HAS_DCF77
-  uint8_t *DCFpulse;                  // pointer on array with DCF pulse bits
-  DCFpulse = DCF77_Frame(nextmin(t)); // load first DCF frame before start
-#elif defined HAS_IF482
-  static TickType_t txDelay = pdMS_TO_TICKS(1000 - IF482_SYNC_FIXUP) -
-                              tx_Ticks(IF482_FRAME_SIZE, HAS_IF482);
-#endif
 
   // output the next second's pulse/telegram after pps arrived
   for (;;) {
 
-    // wait for timepulse and store UTC time in seconds got
-    xTaskNotifyWait(0x00, ULONG_MAX, &printtime, portMAX_DELAY);
-    t = time_t(printtime);
+    // wait for timepulse and store UTC time
+    xTaskNotifyWait(0x00, ULONG_MAX, &current_time, portMAX_DELAY);
 
-    // no confident or no recent time -> suppress clock output
-    if ((timeStatus() == timeNotSet) || !(timeIsValid(t)) ||
-        (t == last_printtime))
+    if ((sntp_get_sync_status() == SNTP_SYNC_STATUS_IN_PROGRESS) ||
+        !(timeIsValid(current_time)) || (current_time == previous_time))
       continue;
 
+    // set calendar time for next second of clock output
+    tt = (time_t)(current_time + 1);
+    localtime_r(&tt, &t);
+    mktime(&t);
+
 #if defined HAS_IF482
 
     // wait until moment to fire. Normally we won't get notified during this
     // timespan, except when next pps pulse arrives while waiting, because pps
-    // was adjusted by recent time sync
-    if (xTaskNotifyWait(0x00, ULONG_MAX, &printtime, txDelay) == pdTRUE)
-      t = time_t(printtime); // new adjusted UTC time seconds
+    // was adjusted by recent time sync, then advance next_time one second
+    if (xTaskNotifyWait(0x00, ULONG_MAX, &current_time, txDelay) == pdTRUE) {
+      tt = (time_t)(current_time + 1);
+      localtime_r(&tt, &t);
+      mktime(&t);
+    }
 
     // send IF482 telegram
-    IF482.print(IF482_Frame(t + 2)); // note: telegram is for *next* second
+    IF482.print(IF482_Frame(t)); // note: telegram is for *next* second
+
+    ESP_LOGD(TAG, "[%0.3f] IF482: %s", _seconds(), IF482_Frame(t));
 
 #elif defined HAS_DCF77
 
-    if (second(t) == DCF77_FRAME_SIZE - 1) // is it time to load new frame?
-      DCFpulse = DCF77_Frame(nextmin(t));  // generate frame for next minute
+    // load new frame if second 59 is reached
+    if (t.tm_sec == 0) {
+      ClockMinute = t.tm_min;
+      t.tm_min++;                  // follow-up minute
+      mktime(&t);                  // normalize calendar time
+      ClockPulse = DCF77_Frame(t); // generate pulse frame
 
-    if (minute(nextmin(t)) ==       // do we still have a recent frame?
-        DCFpulse[DCF77_FRAME_SIZE]) // (timepulses could be missed!)
-      DCF77_Pulse(t + 1, DCFpulse); // then output next second's pulse
+      /* to do here: leap second handling in second 59 */
 
-      // else we have no recent frame, thus suppressing clock output
+      ESP_LOGD(TAG, "[%0.3f] DCF77: new frame for min %d", _seconds(),
+               t.tm_min);
+    } else {
+
+      // generate impulse
+      if (t.tm_min == ClockMinute) { // ensure frame is recent
+        DCF77_Pulse(ClockPulse & 1); // output next second
+        ClockPulse >>= 1;
+      }
+    }
 
 #endif
 
@@ -324,9 +334,66 @@ void clock_loop(void *taskparameter) { // ClockTask
     led1_state = !led1_state;
 #endif
 
-    last_printtime = t;
+    previous_time = current_time;
 
   } // for
 } // clock_loop()
 
-#endif // HAS_IF482 || defined HAS_DCF77
+// we use compile date to create a time_t reference "in the past"
+time_t compileTime(const String compile_date) {
+
+  char s_month[5];
+  int year;
+  struct tm t = {0};
+  static const char month_names[] = "JanFebMarAprMayJunJulAugSepOctNovDec";
+
+  // store compile time once it's calculated
+  static time_t secs = -1;
+
+  if (secs == -1) {
+
+    // determine date
+    // we go one day back to bypass unknown timezone of local time
+    sscanf(compile_date.c_str(), "%s %d %d", s_month, &t.tm_mday - 1, &year);
+    t.tm_mon = (strstr(month_names, s_month) - month_names) / 3;
+    t.tm_year = year - 1900;
+
+    // convert to secs local time
+    secs = mktime(&t);
+  }
+
+  return secs;
+}
+
+static bool IsLeapYear(short year) {
+  if (year % 4 != 0)
+    return false;
+  if (year % 100 != 0)
+    return true;
+  return (year % 400) == 0;
+}
+
+// convert UTC tm time to time_t epoch time
+time_t mkgmtime(const struct tm *ptm) {
+  const int SecondsPerMinute = 60;
+  const int SecondsPerHour = 3600;
+  const int SecondsPerDay = 86400;
+  const int DaysOfMonth[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
+  time_t secs = 0;
+  // tm_year is years since 1900
+  int year = ptm->tm_year + 1900;
+  for (int y = 1970; y < year; ++y) {
+    secs += (IsLeapYear(y) ? 366 : 365) * SecondsPerDay;
+  }
+  // tm_mon is month from 0..11
+  for (int m = 0; m < ptm->tm_mon; ++m) {
+    secs += DaysOfMonth[m] * SecondsPerDay;
+    if (m == 1 && IsLeapYear(year))
+      secs += SecondsPerDay;
+  }
+  secs += (ptm->tm_mday - 1) * SecondsPerDay;
+  secs += ptm->tm_hour * SecondsPerHour;
+  secs += ptm->tm_min * SecondsPerMinute;
+  secs += ptm->tm_sec;
+  return secs;
+}
\ No newline at end of file
diff --git a/src/timesync.cpp b/src/timesync.cpp
index a09bdd04..aa969897 100644
--- a/src/timesync.cpp
+++ b/src/timesync.cpp
@@ -130,7 +130,7 @@ void IRAM_ATTR timesync_processReq(void *taskparameter) {
 
     // calculate average time offset over the summed up difference
     time_offset_ms /= TIME_SYNC_SAMPLES;
-     
+
     // add milliseconds from latest gateway time, and apply a compensation
     // constant for processing times on node and gateway, strip full seconds
     time_offset_ms += timesync_timestamp[sample_idx - 1][gwtime_msec];
@@ -142,9 +142,6 @@ void IRAM_ATTR timesync_processReq(void *taskparameter) {
     time_offset_sec = timesync_timestamp[sample_idx - 1][gwtime_sec];
     time_offset_sec += time_offset_ms / 1000;
 
-    ESP_LOGD(TAG, "LORA date/time: %s",
-             myTZ.dateTime(time_offset_sec, "d.M Y H:i:s.v T").c_str());
-
     setMyTime(time_offset_sec, time_offset_ms, _lora);
 
     // send timesync end char to show timesync was successful