     else if (todaysDate != day())
     {
       yesterdayRuntime = (todaysAccumRuntimeSec / 60);  // Moves today's runtime to yesterday for the app display.
+      Blynk.virtualWrite(112, yesterdayRuntime);        // Record yesterday's runtime to vPin.
       todaysAccumRuntimeSec = 0;                        // Reset today's sec timer.
       Blynk.virtualWrite(111, todaysAccumRuntimeSec);
       hvacTodaysStartCount = 0;                         // Reset how many times unit has started today.

  }

  Blynk.virtualWrite(67, String("returntemp=") + tempRA + "&runstatus=" + runStatus + "&supplytemp=" + tempSA);
}

BLYNK_WRITE(V18)              // App button to display all terminal commands available

    Blynk.virtualWrite(100, minute());
  }
}

int todayTrends[96];  // 0 represents the first 15 minutes of the day, and so on. Will have 96 elements.
int trackTrendIndex;
int yesterdayTrends[96];
bool trackTrendResetFlag;
bool trackTrendMinuteFlag;

void trackTrends()
{
  if (hour() == 0 && trackTrendResetFlag  == 0)   // At midnight...
  {
    int i;
    for (i = 0; i < 97; i++) {                    // ...transfer todayTrends to yesterdayTrends.
      yesterdayTrends[i] = todayTrends[i];
    }

    trackTrendIndex = 0;                          // Reset array index to 0.
    trackTrendResetFlag = 1;
  }
  else if (hour() == 1)                           // Resets flag for the next midnight "reset"
  {
    trackTrendResetFlag = 0;
  }

  if (minute() == 0 && hour() == 0)
  {
    // Do nothing... this would record the previous day runtime (23:45 - 00:00) and we don't want that here.
  }
  else if ( (minute() == 0 || minute() == 15 || minute() == 30 || minute() == 45) && trackTrendMinuteFlag == 0)
  {
    todayTrends[trackTrendIndex] = (todaysAccumRuntimeSec / 60);

    if (todayTrends[trackTrendIndex] = yesterdayTrends[trackTrendIndex])
    {
      // "Trending same runtime as yesterday"
    }
    else if (todayTrends[trackTrendIndex] > yesterdayTrends[trackTrendIndex])
    {
      // "Trending higher runtime today"
    }
    else if (todayTrends[trackTrendIndex] < yesterdayTrends[trackTrendIndex])
    {
      // "Trending lower runtime today"
    }

    ++trackTrendIndex;
    trackTrendMinuteFlag = 1;
  }


  if (minute() == 1 || minute() == 16 || minute() == 31 || minute() == 46)
  {
    trackTrendMinuteFlag = 0;
  }

}
