test.ino

#include "RTClib.h"
#include <Adafruit_MCP23017.h>
#define NUM_ONES_LEDS 4

enum {
  pinFirst = 0,
  pinLast = 15,

  pinJanuary = 0,
  pinFebruary,
  pinMarch,
  pinApril,
  pinMay,
  pinJune,
  pinJuly,
  pinAugust,
  pinSeptember,
  pinOctober,
  pinNovember,
  pinDecember
};

RTC_DS3231 rtc;
Adafruit_MCP23017 mcp3;

void setup() {

  mcp3.begin(B001);
  for (int pin = pinFirst; pin <= pinLast; ++pin) {
    mcp3.pinMode(pin, OUTPUT);
    mcp3.digitalWrite(pin, LOW);
  }

  Serial.begin(115200); // might as well make it fast, your computer is!
  while (!Serial);      // this will stall until Sreial is read

  if (! rtc.begin()) {
    Serial.println("Couldn't find RTC");
    while (1);
  }
  if (rtc.lostPower()) {
    Serial.println("RTC lost power, lets set the time!");
    //rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
  }
}

const char * daysOfTheWeek[7] =
  { "Sunday", "Monday", "Tuesday", "Wednesday",
    "Thursday", "Friday", "Saturday" };

void loop () {
  DateTime now = rtc.now();

  Serial.printf("%d/%d/%d (%s) %2d:%02d:%02d\n",
    now.year(), now.month(), now.day(),
    daysOfTheWeek[now.dayOfTheWeek()],
    now.hour(), now.minute(), now.second()
   );

  Serial.printf("Temperature: %d C",
    rtc.getTemperature()
  );

  if (now.hour() == 10) {
    Serial.println("the hour is 10... writing all HIGH");
    for (int pin = pinFirst; pin <= pinLast; ++pin)
      mcp3.digitalWrite(pin, HIGH);
  }
  else {
    Serial.println("the hour is not yet 10....");
  }

  delay(1000);
}