#include  <NTPClient.h>
  #include  <WiFiUdp.h>

  WiFiUDP   ntpUDP;
  NTPClient timeClient(ntpUDP, "pool.ntp.org", 10800, 60000); // Update every 60 seconds
  unsigned long startMillis; 
  unsigned long syncedMillisOffset;

  void ntp_begin() {
    timeClient.begin();
    timeClient.update();
    // startMillis = millis() - timeClient.getEpochTime() * 1000;
    startMillis = millis();
  }

  void ntp_update() {
    timeClient.update();
  }

  unsigned long ntp_sync_millis() {
    return startMillis + millis();
  }

  String ntp_print_time() {

    // Calculate the time components 
    unsigned long currentMillis = millis();
    unsigned long syncedMillis = currentMillis + syncedMillisOffset;

    unsigned long totalSeconds = syncedMillis / 1000; 
    unsigned long hours = (totalSeconds % 86400) / 3600; 
    unsigned long minutes = (totalSeconds % 3600) / 60; 
    unsigned long seconds = totalSeconds % 60; 
    unsigned long milliseconds = syncedMillis % 1000;

    // Adjust for 12-hour format and determine AM/PM 
    String ampm = "AM";

    if(hours >= 12) { 
      ampm = "PM"; 
      if(hours > 12) 
      hours -= 12; 
    } 
      
    if(hours == 0) { 
      hours = 12; 
    }

    // Generate String
    String x = String(hours) + ":" + String(minutes) + ":" + String(seconds) + ":" + String(milliseconds) + ":" + ampm;

    // Return String Value
    return x;

  }