arduino rtc compile issues

rtc-sample1.ino

/*
 *  
 *  Build on
 *    Arduino 1.6.7
 *    Adafruit RTClib
 *    ...
 */
#include <Wire.h>
#include <Adafruit_LEDBackpack.h>
#include <Adafruit_GFX.h>
#include <RTClib.h>

RTC_DS1307 RTC;
Adafruit_7segment disp = Adafruit_7segment();

void setup()
{
  Wire.begin();
  RTC.begin();
  if (! RTC.isrunning())
  {
    RTC.adjust(DateTime(__DATE__, __TIME__));
  }
  disp.begin(0x70);
}

void loop()
{
  disp.print(getDecimalTime());
  disp.drawColon(true);
  disp.writeDisplay();
  delay(500);
  disp.drawColon(false);
  disp.writeDisplay();
  delay(500);
}

int getDecimalTime()
{
  DateTime now = RTC.now();
  int decimalTime = now.hour() + now.minute();
  return decimalTime;
}