#include <Wire.h>
#include <LiquidCrystal.h>
#include <RTClib.h>

RTC_DS3231 rtc;
LiquidCrystal lcd(2, 3, 4, 5, 6, 7); // (rs, e, d4, d5, d6, d7)


void setup() {
  Serial.begin(9600); 

  lcd.begin(16,2);  

  rtc.begin();       
}

void loop() {
  updateLCD();
}

void updateLCD()
{
  const char dayInWords[7][4] = {"SUN", "MON", "TUE", "WED", "THU", "FRI", "SAT"};

  const char monthInWords[13][4] = {" ", "JAN", "FEB", "MAR", "APR", "MAY", "JUN", 
                                         "JUL", "AUG", "SEP", "OCT", "NOV", "DEC"};
  DateTime rtcTime = rtc.now();

  int ss = rtcTime.second();
  int mm = rtcTime.minute();
  int hh = rtcTime.twelveHour();
  int DD = rtcTime.dayOfTheWeek();
  int dd = rtcTime.day();
  int MM = rtcTime.month();
  int yyyy = rtcTime.year();

  lcd.setCursor(0, 0);

  if (dd < 10) lcd.print("0");  // add preceeding '0' if number is less than 10
  lcd.print(dd);
  lcd.print("-");
  lcd.print(monthInWords[MM]);
  lcd.print("-");
  lcd.print(yyyy);

  lcd.print("  ");
  lcd.print(dayInWords[DD]);

  lcd.setCursor(0, 1);

  if (hh < 10) lcd.print("0");
  lcd.print(hh);
  lcd.print(':');

  if (mm < 10) lcd.print("0");
  lcd.print(mm);
  lcd.print(':');

  if (ss < 10) lcd.print("0");
  lcd.print(ss);

  if (rtcTime.isPM()) lcd.print(" PM"); 
  else lcd.print(" AM");
}