Help with thermostatically controlled relays

I'm having a lot of trouble controlling the relays based on time and temperature. from 8AM to 8PM I want the temp around 90F, turn light off at 92F and back on at 88F. From 8PM to 8AM I want the temp around 80F, turn the light off at 82F and back on at 78F.

I'm using a Arduino Mega 2560, Ethernet shield, 4X20 LCD screen DC3231 RTC, (4X) 10K Thermistors and (2X) relays. LCD connections RS-D12,E-11, D4-D5,D5-D4,D6-D3,D7-D2. thermistors connections A4,A5,A6,A7. RCT connections SDA-SDA D20, SCL-SCL D21. relay connections D8,D9.

code first half..

#include <math.h>
#include <Wire.h>
#include <DS3232RTC.h>
#include <Time.h>  
#include <LiquidCrystal.h>
#include <SPI.h>
#include <Ethernet.h>
#include <Arduino.h>
#define HR1224 6
#define DS3232RTC.h
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
byte mac[] = 
{
  0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED
};
IPAddress ip(192, 168, 1, 177);
EthernetServer server(80);
int RelayL = 8;//Relay Large Tank
int RelayS = 9;//Relay Small Tank
const int HTempSensorPin0 = 4;// A4 Hot Side Large Tank
const int CTempSensorPin2 = 6;// A6 Cold Side Large Tank
const int HTempSensorPin1 = 5;// A5 Hot Side Small Tank
const int CTempSensorPin3 = 7;// A7 Cold Side Small Tank
int     hourFormat12();   
int day();
int month();
int year();
double mytempC4;
double mytempF4;
double mytempC6;
double mytempF6;
double mytempC5;
double mytempF5;
double mytempC7;
double mytempF7;
void setup()
{
  Serial.begin(9600);
  while (!Serial) 
  {
    ;
  }
  SPI.begin();
  Ethernet.begin(mac, ip);
  server.begin();
  Serial.print("server is at ");
  Serial.println(Ethernet.localIP());
  pinMode(RelayL,OUTPUT);  
  pinMode(RelayS,OUTPUT);
  digitalWrite(RelayL,LOW);
  digitalWrite(RelayS,LOW);
  lcd.begin(20, 4);
  lcd.setCursor(4, 1);
  lcd.print("Loading...");
  lcd.setCursor(4, 2);
  lcd.print("Please Wait");
  {
    delay(1000);
  }
  {
    setSyncProvider(RTC.get);   
    if (timeStatus() != timeSet)
    Serial.println("Unable to Sync with RTC");
    else
    Serial.println("RTC has set the system time");
  }
  {
    lcd.clear();
  }
  lcd.begin(20, 4);
  lcd.setCursor(4,0);
  lcd.print("Temps loaded");
  lcd.setCursor(0,1);
  if (timeStatus() != timeSet)
  lcd.print("Unable to Sync with RTC");
  else
  lcd.print("RTC set system time");
  lcd.setCursor(7, 2);
  lcd.print("Done");
  {
    delay(700);
  }
  {
    lcd.clear();
  }
}
double Thermister(int RawADC) 
{
  double Temp;
  Temp = log(((10240000/RawADC) - 10000));
  Temp = 1 / (0.001129148 + (0.000234125 * Temp) + (0.0000000876741 * Temp * Temp * Temp));
  Temp = Temp - 273.15;
  return Temp;
}

byte countr = 1;
void loop()
{
  {
  EthernetClient client = server.available();
  if (client) 
  {
    Serial.println("new client");
    boolean currentLineIsBlank = true;
    while (client.connected()) 
    {
      if (client.available()) 
      {
        char c = client.read();
        Serial.write(c);
        if (c == '\n' && currentLineIsBlank) 
        {
          client.println("HTTP/1.1 200 OK");
          client.println("Content-Type: text/html");
          client.println("Connection: close"); 
          client.println("Refresh: 5");
          client.println();
          client.println("<!DOCTYPE HTML>\n");
          client.println("<html>\n");
          mytempC4 = Thermister(analogRead(4));
          mytempF4 = (mytempC4 * 1.8) + 32.0;
          mytempC6 = Thermister(analogRead(6));
          mytempF6 = (mytempC6 * 1.8) + 32.0;
          mytempC5 = Thermister(analogRead(5));
          mytempF5 = (mytempC5 * 1.8) + 32.0;
          mytempC7 = Thermister(analogRead(7));
          mytempF7 = (mytempC7 * 1.8) + 32.0;
          client.println("<head>");
          client.println("Snake Temps");
          client.println("</head>");
          client.println("<title>");
          client.println("Snake Temps");
          client.println("</title>");
          client.println("<body bgcolor=black>");
          client.println("<font color=white>");
          client.println("<meta http-equiv=\"refresh\" content=\"5\">"); 
          client.println("<center>");                                      
          client.println("<b>");          
          client.println("<td align=center>");
          client.println("<font color = blue size = 15>");
          client.println("Snake Temps");
          client.println("
");
          client.println("<table>");
          client.println("<td align=center>");
          client.println("<font color = blue size = 5>");
          client.println(hourFormat12());
          client.print(':');
          client.print(minute());
          client.print(' ');
          if (isAM())
          {
            client.print("AM");
          }
          if (isPM())
          {
            client.print("PM");
          }
          client.print(' ');
          client.print(month());
          client.print('/');
          client.print(day());
          client.print('/');
          client.print(year());
          client.print(' ');
          client.println("<table>");
          client.println("<td align=left>");
          client.println("<font color = white size = 4>");
          client.println("
");
          client.println(" Large Tank,");
          client.println("
");
          client.println("Hot Side:");
          client.print(mytempC4);
          client.print("C ");
          client.print(' ');
          client.print("- ");
          client.print(' ');
          client.print(mytempF4);
          client.print("F ");
          client.println("
");        
          client.print("Cold Side:");
          client.print(mytempC6);
          client.print("C ");
          client.print(' ');
          client.print("- ");
          client.print(' ');
          client.print(mytempF6);
          client.print("F ");      
          client.println("<table>");
          client.println("<td align=left>");
          client.println("<font color = white size = 4>");
          client.println("
");
          client.println(" Small Tank,");
          client.println("
");
          client.println("Hot Side:");
          client.print(mytempC5);
          client.print("C ");
          client.print(' ');
          client.print("- ");
          client.print(' ');
          client.print(mytempF5);
          client.print("F ");
          client.println("
");        
          client.print("Cold Side:");
          client.print(mytempC7);
          client.print("C ");
          client.print(' ');
          client.print("- ");
          client.print(' ');
          client.print(mytempF7);
          client.print("F ");       
          client.println("");
          client.println("</td>");
          client.println("</tr>");
          client.println("</table>");
          client.println("<p>");
          client.println("<FORM>");
          client.println("<INPUT type=button value=Refresh onClick=window.location='/?reconnect\'>");
          client.println("</FORM>");   
          client.println("<FORM>");    
          client.println("</html>");
          break;
        }
        if (c == '\n') 
        {
          currentLineIsBlank = true;
        } 
        else if (c != '\r') 
        {
          currentLineIsBlank = false;
        }
      }

second half...

 }
    delay(1);
    client.stop();
    Serial.println("client disconnected");
    Ethernet.maintain();
  }
}
  {
  char buffer[10];
  time_t t = now();     
  sprintf(buffer, "%02d:%02d:%02d", hourFormat12(t), minute(t), second(t));
  mytempC4 = Thermister(analogRead(4));
  mytempF4 = (mytempC4 * 1.8) + 32.0;
  mytempC6 = Thermister(analogRead(6));
  mytempF6 = (mytempC6 * 1.8) + 32.0;
  mytempC5 = Thermister(analogRead(5));
  mytempF5 = (mytempC5 * 1.8) + 32.0;
  mytempC7 = Thermister(analogRead(7));
  mytempF7 = (mytempC7 * 1.8) + 32.0;         
  Serial.println(buffer);
  Serial.print(month());
  Serial.print("/");
  Serial.print(day());
  Serial.print("/");
  Serial.print(year());
  Serial.println(" ");
  Serial.println(" ");
  Serial.println("Hot Side Large Tank");
  Serial.print(mytempC4);
  Serial.print("C");
  Serial.print(' ');
  Serial.print(mytempF4);
  Serial.print("F");
  Serial.println(" ");
  Serial.println(" ");
  Serial.println("Cold Side Large Tank");
  Serial.print(mytempC6);
  Serial.print("C");
  Serial.print(' ');
  Serial.print(mytempF6);
  Serial.print("F");
  Serial.println(" ");
  Serial.println(" ");
  Serial.println("Hot Side Small Tank");
  Serial.print(mytempC5);
  Serial.print("C");;
  Serial.print(' ');
  Serial.print(mytempF5);
  Serial.print("F");
  Serial.println(" ");
  Serial.println(" ");
  Serial.println("Cold Side Small Tank");
  Serial.print(mytempC7);
  Serial.print("C");
  Serial.print(' ');
  Serial.print(mytempF7);
  Serial.print("F");
  Serial.println(" ");
  Serial.println(" ");
  } 
   {
    if (isAM())
    {
      lcd.setCursor(5,3);
      lcd.print(" AM ");
    }
    if (isPM())
    {
      lcd.setCursor(5,3);
      lcd.print(" PM ");
    }   
    if (minute()<10)
    {
      lcd.setCursor(2,3);
      lcd.print(":");
      lcd.setCursor(3,3);
      lcd.print("0");
      lcd.print(minute());
    }
    if (minute()>=10)
    {
      lcd.setCursor(2,3);
      lcd.print(":");
      lcd.setCursor(3,3);
      lcd.print(minute());
    }   
    lcd.setCursor(0,3);
    if (hourFormat12() < 10)
    {
       lcd.print("0"); 
       }
       if (hourFormat12() > 12)
       {
          lcd.print("0"); 
        } 
        else 
        {
          lcd.print(hourFormat12()); 
          }
    lcd.setCursor(10,3);
    lcd.print(month());
    lcd.print("/");
    lcd.print(day());
    lcd.print("/");
    lcd.print(year());
    lcd.setCursor(0, 0);
    lcd.print("LG Tank");
    lcd.setCursor(0, 1);
    lcd.print("H");
    lcd.setCursor(11,0);
    lcd.print("SM Tank");
    lcd.setCursor(11, 1);
    lcd.print("H");
    lcd.setCursor(0,2);
    lcd.print("C");
    lcd.setCursor(11, 2);
    lcd.print("C");
    lcd.setCursor(2, 1);
    lcd.print(mytempF4);
    lcd.print("F");
    lcd.setCursor(2, 2);  
    lcd.print(mytempF6);
    lcd.print("F");
    lcd.setCursor(13, 1);  
    lcd.print(mytempF5);
    lcd.print("F");
    lcd.setCursor(13, 2);    
    lcd.print(mytempF7);
    lcd.print("F");
    delay(1000);
  }
}

I don't know how to have if see if it is between two times. I have tried to find examples for hints but couldn't find anything.

if (hour() == 8 && mytempF4 <= 92)
      {
        digitalWrite(8, LOW);
      }
      if (hour() == 8 && mytempF4 <= 88)
      {
        digitalWrite(8, HIGH);

that works but if I try and add more times it doesn't work.

Okay I see what I was doing wrong now, Thank you. I'll go ahead and retry it this way. To add two relays I would do say timeSetPoint1 and timeSetPoint2? also I would have to write this for ==0 && <8 and again for =>20 && <23:59 or 24?

So thats it, all I have to do is write that twice replacing temperature with my mytempF4 and mytempF5 and telling it to turn relays LOW and HIGH for both pin 8 and 9. Thank you so much I have been messing around with this for about 3 nights. its been driving me crazy.