#include <Wire.h>
#include <RTClib.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

RTC_DS1307 RTC;
Adafruit_SSD1306 OLED = Adafruit_SSD1306(128, 64, & Wire);

void setup() {
  Wire.begin();
  RTC.begin();
  OLED.begin(SSD1306_SWITCHCAPVCC, 0x3C);
}

void loop() {
  DateTime now = RTC.now();
  OLED.clearDisplay();
  OLED.setTextColor(WHITE);

  OLED.setTextSize(1);
  OLED.setCursor(0,0);
  OLED.print("TIME");
  OLED.setTextSize(2);
  OLED.setCursor(0,10);
  OLED.print(now.hour() < 10 ? "0" : "");
  OLED.print(now.hour(), DEC);
  OLED.print(":");
  OLED.print(now.minute() < 10 ? "0" : "");
  OLED.print(now.minute(), DEC);
  OLED.print(":");
  OLED.print(now.second() < 10 ? "0" : "");
  OLED.println(now.second(), DEC);
  OLED.setTextSize(2);
  OLED.setCursor(90, 10);

  if (now.hour() < 12) {
    OLED.print(" AM");
  } else if (now.hour() >= 12) {
    OLED.print(" PM");
  }

  OLED.setTextSize(1);
  OLED.setCursor(0,35);
  OLED.print("DATE");
  OLED.setTextSize(2);
  OLED.setCursor(0,45);
  OLED.print(now.month() < 10 ? "0" : "");
  OLED.print(now.month(), DEC);
  OLED.print(".");
  OLED.print(now.day() < 10 ? "0" : "");
  OLED.print(now.day(), DEC);
  OLED.print(".");
  OLED.print(now.year() < 10 ? "0" : "");
  OLED.println(now.year(), DEC);

  delay(100);
  OLED.display();
  OLED.dim(true);
  delay(500);
  OLED.dim(false);
  delay(500);
}