#include <Arduino.h>
#include <string.h>

unsigned int day;
byte hour, min, sec;
unsigned short int mills;
unsigned long mcsTime;

void tick_timer()
{
  mills += 1;

  // in range [0..23]
  if (hour >= 23)
  {
    hour -= 23;
    day += 1;
  }

  // in range [0..59]
  if (min >= 59)
  {
    min -= 59;
    hour += 1;
  }

  // in range [0..59]
  if (sec >= 59)
  {
    sec -= 59;
    min += 1;
  }

  // in range [0..999]
  if (mills >= 999)
  {
    mills -= 999;
    sec += 1;
  }
}

String get_format_time()
{
  String timeStr = "Days: ";
  timeStr.concat(day);
  timeStr.concat(" Hours: ");
  timeStr.concat(hour);
  timeStr.concat(" Minutes: ");
  timeStr.concat(min);
  timeStr.concat(" Seconds: ");
  timeStr.concat(sec);
  timeStr.concat(" Micros: ");
  timeStr.concat(mcsTime);

  return timeStr;
}

void setup()
{
  Serial.begin(115200);
  mcsTime = micros();
}

byte oldSec = 0;
void loop()
{
  if (abs(micros() - mcsTime) >= 1000)
  {
    tick_timer();
    mcsTime = micros();

    if (oldSec != sec)
    {
      Serial.println(get_format_time());
      oldSec = sec;
    }
  }
}