simple arduino based clock without RTC.ino

int h,m,s;
int set_hours=20;
int set_minutes=49;
int set_seconds=45;
int secs=1000;
#include <LiquidCrystal.h>
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup() {
  // put your setup code here, to run once:
  lcd.begin(16,2);
  lcd.print("The Time is!");
    
}

void printChar()
{
   lcd.setCursor(6,1);
    lcd.print(s/10);
    lcd.setCursor(7,1);
    lcd.print(s%10);
    lcd.setCursor(3,1);
    lcd.print(m/10);
    lcd.setCursor(4,1);
    lcd.print(m%10);
    lcd.setCursor(5,1);
    lcd.print(":");
    lcd.setCursor(0,1);
    lcd.print(h/10);
    lcd.setCursor(1,1);
    lcd.print(h%10);
    lcd.setCursor(2,1);
    lcd.print(":");
}


void Clock()
{   
for(h=set_hours;h<24;h++)   //hOURS
  {
for(m=set_minutes;m<60;m++)     //mINUTES
    {
for(s=set_seconds;s<60;s++)     //Seconds
      {
   printChar();
      delay(secs-(millis()%1000));
 }
set_seconds=00;        
 }
set_minutes=00;
}
set_hours=00;  
}
void loop() 
{
Clock();
        }
        
      

This program gives an efficiency of 5seconds shift for every 12 hours due to clock going out of sync. I hope its helpful . Looking forward for corrections and improvements