diff --git a/examples/OneOpenAir/OneOpenAir.ino b/examples/OneOpenAir/OneOpenAir.ino
index 41ffebf..aedf8ee 100644
--- a/examples/OneOpenAir/OneOpenAir.ino
+++ b/examples/OneOpenAir/OneOpenAir.ino
@@ -856,13 +856,23 @@ static void configUpdateHandle() {
 
   fwNewVersion = configuration.newFirmwareVersion();
   if (fwNewVersion.length()) {
-    int lastOta = configuration.getLastOta();
-    if (lastOta != 0 && lastOta < (60 * 60 * 24)) {
-      Serial.println("Ignore OTA cause last update is " + String(lastOta) +
-                     String("sec"));
-      Serial.println("Retry again after 24h");
+    bool doOta = false;
+    if (measurements.otaBootCount == 0) {
+      doOta = true;
+      Serial.println("First OTA");
     } else {
-      configuration.updateLastOta();
+      if ((measurements.bootCount - measurements.otaBootCount) >= 30) {
+        doOta = true;
+      } else {
+        Serial.println(
+            "OTA ignore, try again next " +
+            String(30 - (measurements.bootCount - measurements.otaBootCount)) +
+            String(" boots"));
+      }
+    }
+
+    if (doOta) {
+      measurements.otaBootCount = measurements.bootCount;
       otaHandler.setHandlerCallback(otaHandlerCallback);
       otaHandler.updateFirmwareIfOutdated(ag->deviceId());
     }
diff --git a/src/AgConfigure.cpp b/src/AgConfigure.cpp
index bff679b..ead430e 100644
--- a/src/AgConfigure.cpp
+++ b/src/AgConfigure.cpp
@@ -40,7 +40,6 @@ JSON_PROP_DEF(ledBarBrightness);
 JSON_PROP_DEF(displayBrightness);
 JSON_PROP_DEF(co2CalibrationRequested);
 JSON_PROP_DEF(ledBarTestRequested);
-JSON_PROP_DEF(lastOta);
 JSON_PROP_DEF(offlineMode);
 
 #define jprop_model_default                 ""
@@ -56,7 +55,6 @@ JSON_PROP_DEF(offlineMode);
 #define jprop_postDataToAirGradient_default true
 #define jprop_ledBarBrightness_default      100
 #define jprop_displayBrightness_default     100
-#define jprop_lastOta_default               0
 #define jprop_offlineMode_default           false
 
 JSONVar jconfig;
@@ -162,7 +160,6 @@ void Configuration::defaultConfig(void) {
   jconfig[jprop_noxLearningOffset] = jprop_noxLearningOffset_default;
   jconfig[jprop_abcDays] = jprop_abcDays_default;
   jconfig[jprop_model] = jprop_model_default;
-  jconfig[jprop_lastOta] = jprop_lastOta_default;
   jconfig[jprop_offlineMode] = jprop_offlineMode_default;
 
   saveConfig();
@@ -1073,17 +1070,6 @@ void Configuration::toConfig(const char *buf) {
     jconfig[jprop_offlineMode] = false;
   }
 
-  /** Last OTA */
-  if(JSON.typeof_(jconfig[jprop_lastOta]) != "number") {
-    isInvalid = true;
-  } else {
-    isInvalid = false;
-  }
-  if(isInvalid) {
-    jconfig[jprop_lastOta] = jprop_lastOta_default;
-    changed = true;
-  }
-
   if (changed) {
     saveConfig();
   }
@@ -1167,53 +1153,6 @@ bool Configuration::isDisplayBrightnessChanged(void) {
   return changed;
 }
 
-/**
- * @brief Get number of sec from last OTA
- *
- * @return int < 0 is invalid, 0 mean there is no OTA trigger.
- */
-int Configuration::getLastOta(void) {
-  struct tm timeInfo;
-  if (getLocalTime(&timeInfo) == false) {
-    logError("Get localtime failed");
-    return -1;
-  }
-  int curYear = timeInfo.tm_year + 1900;
-  if (curYear < 2024) {
-    logError("Current year " + String(curYear) + String(" invalid"));
-    return -1;
-  }
-  double _t = jconfig[jprop_lastOta];
-  time_t lastOta = (time_t)_t;
-  time_t curTime = mktime(&timeInfo);
-  logInfo("Last ota time: " + String(lastOta));
-  if (lastOta == 0) {
-    return 0;
-  }
-
-  int sec = curTime - lastOta;
-  logInfo("Last ota secconds: " + String(sec));
-  return sec;
-}
-
-void Configuration::updateLastOta(void) {
-  struct tm timeInfo;
-  if (getLocalTime(&timeInfo) == false) {
-    logError("updateLastOta: Get localtime failed");
-    return;
-  }
-  int curYear = timeInfo.tm_year + 1900;
-  if (curYear < 2024) {
-    logError("updateLastOta: lolcal time invalid");
-    return;
-  }
-  
-  time_t lastOta = mktime(&timeInfo);
-  jconfig[jprop_lastOta] = (unsigned long)lastOta;
-  logInfo("Last OTA: " + String(lastOta));
-  saveConfig();
-}
-
 String Configuration::newFirmwareVersion(void) {
   String newFw = otaNewFirmwareVersion;
   otaNewFirmwareVersion = String("");
diff --git a/src/AgConfigure.h b/src/AgConfigure.h
index 13b7dc0..c3eda36 100644
--- a/src/AgConfigure.h
+++ b/src/AgConfigure.h
@@ -76,8 +76,6 @@ public:
   int getLedBarBrightness(void);
   bool isDisplayBrightnessChanged(void);
   int getDisplayBrightness(void);
-  int getLastOta(void);
-  void updateLastOta(void);
   String newFirmwareVersion(void);
   bool isOfflineMode(void);
   void setOfflineMode(bool offline);
diff --git a/src/AgValue.h b/src/AgValue.h
index 3176482..7446411 100644
--- a/src/AgValue.h
+++ b/src/AgValue.h
@@ -69,6 +69,7 @@ public:
   int countPosition;
   const int targetCount = 20;
   int bootCount;
+  int otaBootCount;
 
   String toString(bool isLocal, AgFirmwareMode fwMode, int rssi, void* _ag, void* _config);
 };
diff --git a/src/AgWiFiConnector.cpp b/src/AgWiFiConnector.cpp
index 669d526..c8a9d8d 100644
--- a/src/AgWiFiConnector.cpp
+++ b/src/AgWiFiConnector.cpp
@@ -1,6 +1,5 @@
 #include "AgWiFiConnector.h"
 #include "Libraries/WiFiManager/WiFiManager.h"
-#include <time.h>
 
 #define WIFI_CONNECT_COUNTDOWN_MAX 180
 #define WIFI_HOTSPOT_PASSWORD_DEFAULT "cleanair"
@@ -159,11 +158,6 @@ bool WifiConnector::connect(void) {
       config.setPostToAirGradient(result != "T");
     }
     hasPortalConfig = false;
-
-    /** Configure internet time */
-    const char *ntp_server = "pool.ntp.org";
-    configTime(0, 0, ntp_server);
-    logInfo("Set internet time server: " + String(ntp_server));
   }
 #else
   _wifiProcess();