#include <WiFi.h>
#include "time.h"
#include "sntp.h"

const char* ssid       = "LSTN";
const char* password   = "act1234567890";

const char* ntpServer1 = "pool.ntp.org";
const char* ntpServer2 = "time.nist.gov";
const long  gmtOffset_sec = 3600;
const int   daylightOffset_sec = 3600;

const char* time_zone = "CET-1CEST,M3.5.0,M10.5.0/3";  // TimeZone rule for Europe/Rome including daylight adjustment rules (optional)

void printLocalTime()
  struct tm timeinfo;
    Serial.println("No time available (yet)");
  Serial.println(&timeinfo, "%A, %B %d %Y %H:%M:%S");

// Callback function (get's called when time adjusts via NTP)
void timeavailable(struct timeval *t)
  Serial.println("Got time adjustment from NTP!");

void setup()

  // set notification call-back function
  sntp_set_time_sync_notification_cb( timeavailable );

   * NTP server address could be aquired via DHCP,
   * NOTE: This call should be made BEFORE esp32 aquires IP address via DHCP,
   * otherwise SNTP option 42 would be rejected by default.
   * NOTE: configTime() function call if made AFTER DHCP-client run
   * will OVERRIDE aquired NTP server address
  sntp_servermode_dhcp(1);    // (optional)

   * This will set configured ntp servers and constant TimeZone/daylightOffset
   * should be OK if your time zone does not need to adjust daylightOffset twice a year,
   * in such a case time adjustment won't be handled automagicaly.
  configTime(gmtOffset_sec, daylightOffset_sec, ntpServer1, ntpServer2);

   * A more convenient approach to handle TimeZones with daylightOffset 
   * would be to specify a environmnet variable with TimeZone definition including daylight adjustmnet rules.
   * A list of rules for your zone could be obtained from https://github.com/esp8266/Arduino/blob/master/cores/esp8266/TZ.h
  //configTzTime(time_zone, ntpServer1, ntpServer2);

  //connect to WiFi
  Serial.printf("Connecting to %s ", ssid);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
  Serial.println(" CONNECTED");


void loop()
  printLocalTime();     // it will take some time to sync time :)