#include <DS3231.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);
DS3231 rtc;

bool mode12 = false;
byte theSecond = 55;
byte theMinute = 01;
byte theHour = 20;
byte theWday = 0;
byte theDate = 8;
byte theMonth = 3;
byte theYear = 24;

bool h12;
bool hPM;
bool CenturyBit;
char* myWday[] = { "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun" };
char* myMonth[] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul",
                    "Aug", "Sep", "Oct", "Nov", "Dec" };

void setup() {
  Serial.begin(9600);
  lcd.init();
  lcd.backlight();
  rtc.setClockMode(mode12);
  rtc.setSecond(theSecond);
  rtc.setMinute(theMinute);
  rtc.setHour(theHour);
  rtc.setDoW(theWday);
  rtc.setDate(theDate);
  rtc.setMonth(theMonth);
  rtc.setYear(theYear);
}

void loop() {

  byte cnt_S = rtc.getSecond() % 2;
  byte myHH = rtc.getHour(h12, hPM);
  byte myMM = rtc.getMinute();
  byte mySS = rtc.getSecond();
  byte myDW = rtc.getDoW();
  byte myDD = rtc.getDate();
  byte myMT = rtc.getMonth(CenturyBit);
  byte myYY = rtc.getYear();
  float lcdTemp;
  float rtcTemp = rtc.getTemperature();
  if (rtcTemp > -9999) {
    lcdTemp = rtcTemp;  // it may be OK to use the returned value
  } else {
    lcdTemp = 0;        // the value returned is not valid
  }

  lcd.setCursor(0, 1);
  for (myDW;;) {
    lcd.print(myWday[myDW]);
    break;
  }
  lcd.print(char(144));
  if (myDD < 10) { lcd.print('0'); }
  lcd.print(myDD);
  lcd.print(char(144));
  for (myMT;;) {
    lcd.print(myMonth[myMT]);
    break;
  }
  lcd.print(char(144));
  lcd.print("20");
  lcd.print(myYY);
  lcd.setCursor(0, 0);
  if (myHH < 10) { lcd.print(0); }
  lcd.print(myHH);
  if (cnt_S < 1) { lcd.print(':'); }
  if (cnt_S > 0) { lcd.print(char(165)); }
  if (myMM < 10) { lcd.print(0); }
  lcd.print(myMM);
  if (cnt_S < 1) { lcd.print(':'); }
  if (cnt_S > 0) { lcd.print(char(165)); }
  if (mySS < 10) { lcd.print(0); }
  lcd.print(mySS);
  if (mySS > 10) { lcd.print(char(144)); }
  lcd.setCursor(9, 0);
  lcd.print(lcdTemp);
  lcd.print(char('C'));
  lcd.print(char(223));
}