unsigned long startMillis = millis();
while (millis() - startMillis < LONG_DELAY_MS);

#include <avr/sleep.h>
// This variable is made volatile because it is changed inside an interrupt function
volatile int sleep_count = 0; // Keep track of how many sleep cycles have been completed.
const int interval = 720; // Interval in minutes between waking and doing tasks.
const int sleep_total = (interval*60)/8; // Approximate number of sleep cycles
// needed before the interval defined above elapses. Not that this does integer math.

void setup(void) {
    watchdogOn(); // Turn on the watch dog timer.
    // Disable the ADC by setting the ADEN bit (bit 7) to zero.
    ADCSRA = ADCSRA & B01111111;
    // Disable the analog comparator by setting the ACD bit (bit 7) to one.
    ACSR = B10000000;
    // Disable digital input buffers on all analog input pins by setting bits 0-5 to one.
    DIDR0 = DIDR0 | B00111111;
}

void loop(void) {
    goToSleep(); // ATmega328 goes to sleep for about 8 seconds
    // and continues to execute code when it wakes up
    if (sleep_count == sleep_total) {
        // CODE TO BE EXECUTED PERIODICALLY
    }
}

void goToSleep() {
    set_sleep_mode(SLEEP_MODE_PWR_DOWN); // Set sleep mode.
    sleep_enable(); // Enable sleep mode.
    sleep_mode(); // Enter sleep mode.
    // After waking from watchdog interrupt the code continues
    // to execute from this point.
    sleep_disable(); // Disable sleep mode after waking.
}

void watchdogOn() {
    // Clear the reset flag, the WDRF bit (bit 3) of MCUSR.
    MCUSR = MCUSR & B11110111;
    // Set the WDCE bit (bit 4) and the WDE bit (bit 3) of WDTCSR.
    WDTCSR = WDTCSR | B00011000;
    // Set the watchdog timeout prescaler value to 1024 K
    // which will yeild a time-out interval of about 8.0 s.
    WDTCSR = B00100001;
    // Enable the watchdog timer interupt.
    WDTCSR = WDTCSR | B01000000;
    MCUSR = MCUSR & B11110111;
}

ISR(WDT_vect)
{
    sleep_count ++; // keep track of how many sleep cycles have been completed.
}

for (unsigned int bigloop=0; bigloop<65535; bigloop++)
{
   for (unsigned int smallloop=0; smallloop<65535; smallloop++)
   {
      for (unsigned int tinyloop=0; tinyloop<65535; tinyloop++)
      {
         delay(65535);
      }
   }
}

longDelayInSeconds = 120; //two minutes;
while (p < longDelayInSeconds) {

        delay(1000);
        p++;

}

for (int Hours = 0; Hours < 12; Hours++) {            //Creates 12 hours
  for (int Minutes = 0; Minutes < 60; Minutes++) {    //Creates 1 hour
    for (int Seconds = 0; Seconds < 60; Seconds++) {  //Creates 1 minute
      delay(1000);                                    //Creates 1 second
    }
  }
}