Dot Matrix Clock With NTP Server Using ESP32

Okay it works now. Here you go. For reference. Sorry, I just learned Arduino yesterday. So total newbie.

/*
Project: Dot matrix clock with NTP server using ESP32
Board: ESP32 Dev Module (Node32 Lite)

Connections:
ESP32 | Dot Matrix
RAW – VCC
GND – GND
27 – DIN
26 – CS
25 – CLK

External libraries:
– MD_MAX72XX by majicDesigns Version 3.2.1 (Manager)
– MD_Parola by majicDesigns Version 3.3.0 (Manager)
– NTPClient by Fabrice Weinberg Version 3.1.0 (Zip)
https://github.com/taranais/NTPClient/archive/master.zip
*/

#include
#include
const char ssid[] = “wifi name”; // WiFi name
const char password[] = “password”; // WiFi password

#include
#include
WiFiUDP ntpUDP;
NTPClient timeClient(ntpUDP);

#include
#include
#include

//#define HARDWARE_TYPE MD_MAX72XX::FC16_HW
#define HARDWARE_TYPE MD_MAX72XX::FC16_HW
#define MAX_DEVICES 4
#define CLK_PIN 25 // 18 or 25
#define DATA_PIN 27 // 16 or 27
#define CS_PIN 26 // 17 or 26

MD_Parola DotMatrix = MD_Parola(HARDWARE_TYPE, DATA_PIN, CLK_PIN, CS_PIN, MAX_DEVICES);

uint8_t scrollSpeed = 50; // default frame delay value
textEffect_t scrollEffect = PA_SCROLL_LEFT;
textPosition_t scrollAlign = PA_LEFT;
uint16_t scrollPause = 3000; // in milliseconds

long currentMillis = 0;
long previousMillis = 0;
int interval = 1000;
String formattedDate;
String timeStamp, hour, minute, second;
String dateStamp, year, month, date;
char dateBuffer[] = “”;
String monthArray[12] = {
” Jan “, ” Feb “, ” Mar “, ” Apr “, ” May “, ” Jun “,
” Jul “, ” Aug “, ” Sep “, ” Oct “, ” Nov “, ” Dec ”
};
enum {TIME, DATE};
boolean displayMode = TIME;

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());

DotMatrix.begin();
DotMatrix.setIntensity(0);

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

DotMatrix.displayText(“NTP Clock by Idris”, scrollAlign, scrollSpeed, scrollPause, scrollEffect, scrollEffect);
displayMode = DATE;
}

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

if (displayMode == DATE && DotMatrix.displayAnimate()) {
DotMatrix.displayReset();
displayMode = TIME;
}

currentMillis = millis();
if (currentMillis – previousMillis > interval &&
displayMode == TIME) {
previousMillis = millis();

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

// Extract date
year = formattedDate.substring(0, 4);
month = formattedDate.substring(5, 7);
month = monthArray[month.toInt() – 1];
date = formattedDate.substring(8, 10);
date = String(date.toInt());
dateStamp = year + “, ” + date + month;
dateStamp.toCharArray(dateBuffer, dateStamp.length()+1);

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

if (hour.toInt() == 0) {
hour = String(hour.toInt() + 12);
}
else if (hour.toInt() < 13) {
hour = String(hour.toInt());
}
else {
hour = String(hour.toInt() – 12);
}

if (second.toInt() == 0) {
displayMode = DATE;
DotMatrix.displayClear();
DotMatrix.displayText(dateBuffer, scrollAlign, scrollSpeed, scrollPause, scrollEffect, scrollEffect);
return;
}
else if (second.toInt() % 2) {
timeStamp = hour + ":" + minute;
}
else {
timeStamp = hour + " " + minute;
}

DotMatrix.setTextAlignment(PA_CENTER);
DotMatrix.print(timeStamp);
}
}

I got an error on line 129. Can somebody please help me by telling whats wrong with that line?

hour = String(hour.toInt() – 12);