WS2812 Ring LED clock with NTP server using ESP32

ESP32NTPClockRingLED.ino

/*
  Project: WS2812 Ring LED clock with NTP server using ESP32
  Board: ESP32 Dev Module (Node32 Lite)
  
  Connections:
  ESP32 | OLED Strip
    RAW - VCC
    GND - GND
     25 - DIN
  
  External libraries:
  - NeoPixelBus by Micheal C. Miller V2.5.7 (Manager)
  - NTPClient by Fabrice Weinberg V3.1.0 (Zip)
    https://github.com/taranais/NTPClient/archive/master.zip
 */

#include <WiFi.h>
#include <WiFiClient.h>
const char ssid[] = "Your WiFi SSID"; // WiFi name
const char password[] = "Your WiFi Password"; // WiFi password

#include <NTPClient.h>
#include <WiFiUdp.h>
WiFiUDP ntpUDP;
NTPClient timeClient(ntpUDP);

#include <NeoPixelBrightnessBus.h>
#define PIN   25
#define NUMPIXELS 60
NeoPixelBrightnessBus<NeoGrbFeature, Neo800KbpsMethod> strip(NUMPIXELS, PIN);

long currentMillis = 0;
long previousMillis = 0;
int interval = 1000;
String formattedDate;
int hour, minute, second;
int hour1, hour2, hour3;

void setup()
{
  Serial.begin(115200);

  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("");
  Serial.println("WiFi connected.");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());

  strip.Begin();
  strip.SetBrightness(5);
  clockSegment();
  strip.Show();

  timeClient.begin();
  timeClient.setTimeOffset(28800); // Set offset time in seconds, GMT+8 = 28800
}

void loop()
{
  while (!timeClient.update()) {
    timeClient.forceUpdate();
  }

  currentMillis = millis();
  if (currentMillis - previousMillis > interval) {
    previousMillis = millis();

    // Clear all leds
    strip.SetPixelColor(hour, RgbColor(0, 0, 0));
    strip.SetPixelColor(hour+1, RgbColor(0, 0, 0));
    strip.SetPixelColor(hour+2, RgbColor(0, 0, 0));
    strip.SetPixelColor(hour+3, RgbColor(0, 0, 0));
    strip.SetPixelColor(hour+4, RgbColor(0, 0, 0));
    
    strip.SetPixelColor(minute, RgbColor(0, 0, 0));
    strip.SetPixelColor(second, RgbColor(0, 0, 0));
    
    strip.Show();

    // The formattedDate comes with the following format:
    // 2018-05-28T16:00:13Z
    formattedDate = timeClient.getFormattedDate();
    Serial.println(formattedDate);

    // Extract time
    hour = formattedDate.substring(11, 13).toInt();
    minute = formattedDate.substring(14, 16).toInt();
    second = formattedDate.substring(17, 19).toInt();

    if (hour > 11) {
      hour = hour - 12;
    }
    hour = (hour * 5) + (minute / 12);
    
    hour1 = hour;
    if (hour == 59) {
      hour2 = hour - 1;
      hour3 = 0;
    }
    else if (hour == 0) {
      hour2 = 59;
      hour3 = hour + 1;
    }
    else {
      hour2 = hour - 1;
      hour3 = hour + 1;
    }
    
    clockSegment();

    strip.SetPixelColor(second, RgbColor(0, 0, 255));
    strip.SetPixelColor(hour1, RgbColor(255, 0, 0));
    strip.SetPixelColor(hour2, RgbColor(255, 0, 0));
    strip.SetPixelColor(hour3, RgbColor(255, 0, 0));
    strip.SetPixelColor(minute, RgbColor(0, 255, 0));
    
    strip.Show();
  }
}

RgbColor DimWhite(50, 50, 50);
void clockSegment()
{
  strip.SetPixelColor(0, DimWhite);
  strip.SetPixelColor(5, DimWhite);
  strip.SetPixelColor(10, DimWhite);
  strip.SetPixelColor(15, DimWhite);
  strip.SetPixelColor(20, DimWhite);
  strip.SetPixelColor(25, DimWhite);
  strip.SetPixelColor(30, DimWhite);
  strip.SetPixelColor(35, DimWhite);
  strip.SetPixelColor(40, DimWhite);
  strip.SetPixelColor(45, DimWhite);
  strip.SetPixelColor(50, DimWhite);
  strip.SetPixelColor(55, DimWhite);
}